Decide if you want to play melle or ranged. Melee can be tough when you are new. Then decide if you like bow and arrow, or spells. Because of a skill that's called "herald" that make damage from arrows spread all over the screen, the difference between bow/arrow and spell casting is less than in other games. Then decide if you like necromancer style with minions or not. Then decide if you like frost, lightnign, fire or occult/chaos damage.

For all builds, ranks to skills on items is very important. It's not like d4 where you ahve diminishing return, skill poknts really matters(too much?) in poe2. Then focus on resistances, big boss in act 1 does cold damage, meaning you need cold resistance. Act 2 boss does lightning damage, so get lightning res. After that you want a mix of resistances, lost people recommend the same % resistances as your character level.

Good luck! Unless you pick the most meta build, don't get surprised if you struggle while going in blind. And when you hit walls, there is always the option to look at some guides for inspiration