lvl 84 low dps

ok i am level 84 on my stormweaver but my dps s only 8900 how do i get it higher

I would suggest following a build guide for starters as long as it's a good guide it should show you what you need to know to have acceptable stuff.

Good chars need good skill choices, increased damage sources, and more multipliers with solid defenses. That's about as complicated as it is. Some of the items you might need to pull that off can be very expensive to trade for that's why I'd suggest following a solo self found build if your new even some of those can assume you know how to get items while ssf.