Chances of being Chaptered under UCMJ?

ok so i was wrongfully accused for assaulting someone at the bar. tried going to JAG but they told me i couldn't do anything until it goes to UCMJ because ultimately they are the ones who will punish me, and i was wondering if i were to be charged what type of punishment am i looking at? also this would be first time i ever have any incident or get charged for anything will that play any part in it? also this happened in germany with german civilian so german police automatically charged me without questioning me but chain of command said they will go through report so want most likely outcome also im an e-3 was supposed to be getting my e-4 which i know is gone now