Got my sample ballot.

So I got my ballot and I'm looking over all of my voting options and looking online for info on these candidates stances and such. This is pretty taxing. I'm kind of stuck on choosing the 2 senate seats and mayor. I know is important so I don't want to just pick anyone. Do any of you have some insight on some of the candidates, shed some light on their stances for me? Also what's up with prop 50? Thanks for your help.