How much should I put in the bank? (+ other ?s)?

I have $88 saved up I'm 15 almost 16 in 1 month I honestly don't need to spend any of it except I really want to get my ear lobes pierced a 3rd time & want to pay it myself I'd ask it for my birthday bu I'd like something more special (not expensive) for my birthday. Should I put half of it in the bank or like 65%? Cause I'd still like to have some money on me for spending but it'll be 2 years left til I graduate. Thanks c: