What to do once 80?
1. Berserker refers to the combination of stats on your items. Each item set at 80 has 3/4 different stats in different combinations. Berserker is preferred by many people because it provides power, precision, and ferocity for high dps without regards to conditions.
2. Purchasing gear can get a bit expensive if you do it all the time so I suggest you start crafting items. Since you’re a Revenant, you probably want to start with armorsmithing and weaponsmithing so that you can make your own weapons and armor. Eventually, you’ll want to max these crafting skills out so you can make ascended items, the tier of items above exotics. If you need a lot of gear in the short term, farming for gold and buying armor of the trading post is probably your best bet until you can make your own.
No specific order.
1). Mastery exp and levels.
2). Elite specs by doing the Hero Challenges in the new zone – gives +10 skill points each.
3). Full exotic set with desired stats. If you’re good enough at dodging, and knowing when to use skills, give berserker gear a shot, otherwise start defensive and slowly replace pieces until you’re somewhere you can handle without getting killed too much. Get them through dungeons, drops, or straight out buying.
4). Ascended armor by killing world bosses daily, or crafting if you want to spend hundreds of gold.
5). Help your guild with the Guild Hall stuff.
6). Achievements. Jumping puzzles, crafting, weapon kills, slayer kills, etc, etc, etc.
7). Make a new character.
I wouldn’t use gold to gear your character (on the trading post). Gold is the most valuable currency. You can get exotic or even ascended gear in a lot of ways, like dungeon tokens, karma, laurels, WvW badges, fractal relics, and so on. It can be good to mix and match methods if you don’t have a lot of any one currency. Karma has very little use, so that’s a good place to start getting gear.