Guild Wars 2

So for the trait trees, I was thinking of leveling out both earth and fire (i generally use a D/D elementalist) and I was wondering if anyone has used this or has a better idea to put the other trait points in (i just got to level 21, haha).

Thanks so much to all of you!

I just started to play Guild Wars 2 and I created an Elementalist. I was wondering, is using a staff or a scepter and off-hand weapon better? Thanks for the help to whoever aids me :’D