Depends on the role you like to play. Some players like monster more than Hunter.
Monster and Assault are straight forward: Deal as much damage as possible to your target (means getting a down on a hunter as a monster or dishing out as much damage as you can in a rapid amount of time as an assault).
Med/Support both have nuances you have to learn, when to heal and/or shield (if possible).
Trapper's still one of the most complex classes in the game, not as logistical as it was in Legacy, but still one of the most pain in the ass classes to play generally.
Generally here's some tips regardless of the class:
Play the tutorials, they teach you the most basic of the basics and you get Markov and the Goliath for free if you do plus a shitload of creds to buy stuff with.
Perks: The combination of perks can make or break a character/team. Experiment and see what works for you. I use a wide range of perks for different characters to make up for their short comings, such as Crow and quick switch.
Haul ass at stage 1, don't go out of your way to look for a fight, if they get into your smell range and you aren't using smell range perks, quickly get a down (or two) then get the hell out of dodge unless you're comfortable about your chances (that's rare for new players). I play with a threshold for armor, if its above a certain point I'll stay in and fight as much as possible unless its not beneficial to me (strikes and dealing damage fill up the evolve meter), if it falls below that I jet. Ability combos is something you're going to need to learn, at the top of your UI as a monster you have 4 "buttons" these are your abilities. You need to chain abilities to get a down effectively. You should experiment and see what works, some have utilitarian uses such as Behemoth with the Rock Wall or Wraith with the phantom. Others are pure offense such as Behemoth's Lava Bomb & Fissure and the Wraith's Supernova & Warp Blast. Evolve to stage 2 and then armor up, then start building strikes to make the combat later at Stage 3 easier. The above also applies here, keep a threshold of armor. Target prioritization is also something you be aware of. Sometimes it'd be better to gun for Hank instead of gunning for the Medic, because of the shields. Other times, it'd be a good idea to go for the trapper to neutralize the CC. Other times, if the shield is down, gun for the assault to eliminate the source of heavy damage to you. Generally, my times for getting a Stage up are at 1:40 or so into the game I'm either Stage 2 (depends on the monster) or in my first dome - this is regardless of the map. When dealing with randoms, I'll be Stage 3 at around the 5 minute mark, with a decent/good team it'll be at that 8 minute mark. This is a benchmark for the competitive-level players. Its not necessarily reflective of what other players times are. You should also experiment with Ability builds and see what works for you. Max out a single Ability at Stage 2, don't spread like you do at Stage 1.
Hunter: Save your jetpack. Only dodge when necessary and make sure to keep your positioning as much as possible. The Assault should be in the monster's face, the Trapper should be behind the monster 9 times out of 10, the only exceptions to this are Abe (AoE CC), Crow (stasis; not hard CC), and Jack (front-facing CC), the Medic should have a wide birth, the only exception is Slim, as he needs to be in the monster's face. Support should be like the Medic, slightly away, but close enough to be useful, which again, depends on the support. Make cuts, you won't catch the monster unless you cut across the terrain. Don't separate yourself from your team either, being overly aggressive will get you killed. Spread out. I can't stress that enough, the medic can't keep everyone up if everyone's going down constantly.
This is just pure unadulterated combat. You're stuck in the dome, so fight. The above applies if you are in a dome.
The easiest characters to play by sub-type:
Medic: Val; straight forward, you got your medgun for healing, the sniper rifle to put out targets for bonus damage for the team, tranq for Crowd Control, the medic class ability is heal burst, use it for an extra burst of health to get people back out of the red... more or less spam it if necessary.
Support: Hank; again straight forward, he has a shield projector for defense, his primary weapon the laser cutter, which deals okay damage, and the orbital barrage for peeling/support. The shield burst gives shields to everyone within a 30 meter radius. You should only shield for abilities or if someone desperately needs it (such as if they're in the red).
Trapper: Maggie; She has Daisy (the dog) which is handled by the AI, she'll track the monster for you, give everyone a speed boost within a 15m radius, and can rez people while your attention is else-where. Her primary is the machine pistol, you should burst-fire this at a moderate range and go full-auto up close. When you empty a mag/clip, cycle to your Harpoon Traps and plop one down in a reasonable location. The Harpoon Trap layer provides CC in the form of harpoons. Stay behind the monster if you can at a moderate range, not too close, not too far. The class ability gives you a beat on where the monster actually is, it also gives you a speed boost. So use it in a hairy situation to get out of it.
Assault: Markov; he does damage to the monster, use the lightning gun up close and cycle to the Assault Rifle if Mines are already out and the LG needs to recharge. The AR has good range, but its inferior to the LG in terms of raw damage potential, it should only be used if Mines are out and the LG is on recharge. Put. Out. Your. Mines. I can't stress that enough. His class ability gives him a shield that halves damage any you take to your health, so don't be afraid to pop it if you're under heavy pressure.
Monster: Goliath/Meteor Goliath; it (its referred to as a "he" even though monsters are genderless) has the following:
Rock Throw: Does a massive amount of damage, but it can be easily stiffed by other hunters. Be wary of the Assault cock-blocking your boulder. You should play it smart and move around before priming it.
Leap Smash: Again DPS handler. Use it from a high cliff or an opener, and try to pop it on someone who is landing from a cliff-face or from tinkerbelling.
Fire Breath: Your standard clearer that does DoT. You'd be best with just one point because of the lack of burst damage on the ability, but it would be useful spending another point on it depending on the comp you're dealing with.
Charge: Does a charge attack that does a decent chunk of health to Hunters. Its a straight line.
Cut off hunters with Traversals if they attempt to run away from you. Keep in mind you're faster than the hunters, so use that to your advantage. Meteor is very similar to OG Goliath, but it does less burst damage, he's faster, sets everything he hits with an ability on fire, and slower cooldowns.
What it really comes down to is what you like. Experiment in solo and earn some creds while you're at it while you learn the game. Co-Op is a good way to earn the creds, because the game is far less brutal there than in a multi-player match, so you should stick to killing bots until you get the times and positioning down. It'll save you some trouble. If someone else wants to explain perks, by all means.
I know this is a lot of information to dig into all at once, but its an enjoyable game once you get past the surface stuff out of the way. Enjoy.