Some questions from an old player

[relampz]

Just came back to the game after about 2 years, and i have a question: what to do? The last time i played the ap people used to have was 600, and it was so broken. I might level a new class, maybe the gunner. Any tips for what to do to get to the end game without problems?

[Ludicium]

Welcome back =) 
Luckily, leveling up in the game is a lot more forgiving now, gearing for endgame however, isn't.
But with that being said, just focus on completing the story, by the end of it, you should get your MSP soul shield (first legendary set), and a legendary weapon (baleful or seraph) - this should leave you with about 800AP.
A few tips along the way, try not to worry about money as by the end of the story line, you should end up with about 100G - which is some nice starting cash.

Later in the game (50+), you will receive lucent sets (equipment) from quest rewards, keep them, you can trash/sell/salvage everything else.

Once you've completed your storyline, head to Solak - Valindria, there is a mechant there that sells Hollow accessories, get those (can cost quite a bit so save up those Naryu Silvers - you definitely don't have to purchase them all at once) - however, you'd only want to get these once you've acquired a 6-gem slot on your legendary weapon, if you don't get it first try, you can head to Silverfrost mountains - Grand Harvest Square, there is a Naryu coin vendor there, keep purchasing the boxes and opening them until you get it (GL).

And that's about all the tips you'd maybe want to keep an out for, for now. Gearing up for endgame takes a loooot of time, and is extremely harsh on new/returning players, so don't rush. Pace yourself.

[Shuchin]

With the recent changes, daily challenge will be a major source of easy upgrading materials, so keep doing that once you reach 55. It's also very easy to finish because of quests like Celestial BAsin and Koldrak which count towards the 3 per day.

 

Once you know a bit better which part of end game you are going for (12-man dungeons? 6v6?) I am sure we can also give you more specific tips on how to get you geared up for that. :)