Fresh 80
Depends on your playstyle, and what you like to do in WvW.
For PvE zerker is and always will be the meta build.
I’d recommend Berserker gear first since you want to PvE.
Then, try that Berserker gear in WvW (but be carefuly with your squishy self). If you enjoy it … yay, done. If not, start to tweak for more/less survivability … changing from power to condition … being more of a hybrid … etc.
You’ll only know what you enjoy in WvW by trial and error.
Try your best to not make mistakes, but, when you do make mistakes, learn from them.
Better yourself.
Don’t just assume your build is wrong just because you died quickly in WvW, either.
Practice a lot first and don’t get discouraged. WvW is extremely fast with the kills and damage output, so consider why you died before re-investigating gear/build choices. When you find yourself without any answers is when you might need to make changes, although even then it usually comes in the form of skill order (possibly conserving your QZ for a stunbreak if you see a thief/warrior coming at you, and so on, or just replacing it with LR if you feel it more useful). Sometimes it’s just a matter of adapting to/knowing your weaknesses and working your hardest to make those weaknesses less exploitable by your enemies.
https://forum-en.gw2archive.eu/forum/professions/thief/ES-Suggestion-The-Deadeye-FORMAL/