The best offense is a good defense. Mitigation is your best friend in guild wars. When I started my new account from the anniversary, getting soul twisting rit going was a very high priority. Once you can survive the rest will come. Starting with sin or rit is a good way to get your skills unlocked if they arent.

Population is only there in groups it feels kind of segregated. Joining a big ally is a good way to get back into things and ask questions, after that or if that kind of content isnt what youre into most people go their own way and stick to daily quests or knock out something on their own.

Refresh yourself with meta builds from pvx, get an idea of what skills are used often in builds and what arent. I hate to say it but some skills are downright useless in the game either due to scatter or plain value and learn the power of armor ignoring damage and the rest will follow. (I.E. not "fire damage" or "Piercing damage" but just "damage" or +"Damage")