But in reality there is no reason to start from zero after a long break. imo GW2 is an awful game to ''start fresh'' on. The experience across the board is just more fun without the limitations of levels/traits and activities you have access to, even if you go back to low level stuff.
Posted January 16, 2018. As other people said what you need to do is level up. As you gain levels you'll also get Hero Points which can be spent to unlock skills and traits (passive skill lines basically). Levelling from 1-80 will get you enough Hero Points to unlock all the core skills and trait lines.
Get some Gear. After that, you should get some gear. Exotic gear is orange in color and it is incredibly strong for its price point. You can find exotic gear for a few GW2 gold pieces on the Black Lion Trading Post. Having level 80 stats will drastically improve your capabilities in any end-game mode.
Select crafting professions and level them up. Get some cool looking armor and dyes for your character. Select a legendary weapon you like and you can start working towards that SLOWLY. (This is a really slow process or can be fast and expensive :D ) If you like fractals you can do them.