Hi! In my opinion you should decide on witnesses based on their work for the community. Some of them develop interesting projects such as @mahdiyari (developer of @steemauto), @prc (for @dsound), @therealwolf (for @smartsteem), @stoodkev (for @steemplus), also @curie and @qurator... Many many more. Just take a look at the witnesses pages and their witnesses threads and do your own research :)

My advise for you is just to let it be for a while, and with time you'll find interesting projects from witnesses you think deserve your vote :) you don't have to cast them now and you don't have to cast the 30 votes at once. I didn't yet cast my 30 votes, since I want to know exactly who I'm voting for and what do they do to help the platform.