My question involves criminal law for the state of: California

Yesterday I was caught shoplifting at Walmart about 50$ worth of items... I was walking out of the store when they stopped me and took me to a little room right off the front of the store... No cops were involved I did return the items they did take down my information but said I should be receiving a letter in a few weeks in the mail but told me it was a warning... This was my first time ever trying to shoplift and got caught. I feel so stupid and ashamed. My question is what should I be expecting besides a fine??