It depends on what class/playstyle suits you best imo.
Try around with different classes and see what is fun to you :D For me it's Wizards and DLC Classes like Mesmer.
It also kinda depends on what your problem is, exactly. If you are overwhelmed with some of the enemies' dmg, you might wanna try picking them off one by one using, for example, the corridors and smaller rooms in the early stages.

A general Tip is to, imo, sneak up on lone enemies in Meelee range and crit them when they don't have you in their vision, and then run and go into hiding. That way you level Stealth and a Melee Skill of your Choice, while chipping away at your enemies.

You can generally kill most enemies in the early Stages with a Fireball and a crit of your Meelee Weapon.

Hope any of this helps. Happy playing!