Lvl 40 Warrior
You should use the traits “Join the Queensdale train to level up faster”, “Start playing WvW to level up faster”, “Do map completion to level up faster”, “Craft like a madman to get 10 levels from one profession taken to 400”, or any other such trait that you feel is to your taste.
The point is – get to lvl 80 and then worry about your build. Before that you don’t have access to top gear and it’s really not worth it to invest in lower level max gear since you outlevel it in a few days and then you need to buy new one which you will again outlevel etc etc.
I think I just put all my points into Power and Precision traitlines when I was levelling my warrior, the first 2 from the top. Maybe add some toughness for more survivability if you feel is needed. As for traits… Just use the ones you feel help your playstyle most; you don’t have access to some traits, anyhow.
I usually go for whatever traits I think look interesting and which synergise well with what armor I’m wearing/weapons I’m using. Generally, I like a hybrid build, so whatever I’m lacking, I’ll trait for.
But, on a Warrior, the fastest way to level up (doing general open world content) is to shove all your traits into Power and Precision and go crazy on the mobs in PvE and get your maps and events completed.