I recently got arrested for retail theft but the item was only 20 dollars but this is also my second offence what do you think will happen oh it's a misdemeanor

A fine, repay for the item if not usable. And probation.

( my guess) I have seen our local judge give a few days jail, to shock them a few times, but not normally

Petty with a prior not good how long between arrest less than a year ? Three missdaminors of the same charge is a fellony were you on probation when this accurd ?if yes they could give you a year taking things that don't belong to you is a no no some judges hate petty theifes and like to make an example out of them