I dont know what will happen to me.
If you haven't informed your husband about this incident, do so before he hears about it from his chain of command.
Several things MIGHT happen to you, as each case is handled individually.
You could be banned from AAFES shopping (including the shopettes) for a year or two.
You will probably have to pay a fine through the US Magistrate on base, or at the appropriate courthouse. Once you receive the papers from the US Attorney, make sure you read them and do as instructed. You DON'T want to miss any court dates.
You'll be required to pay the assessment the AP or store security agent spoke to you about.
Your husband will be notified, and in some cases it can affect his carreer and promotion prospects.
If a child was with you when you allegedly did this "deed", you might receive a visit from your base child services (or state child services agency).
In some cases, you could be banned from being on base, or even ordered to return to CONUS (as in the continental 48) and be denied entry to any military installation for a year, up to three years.
You'll probably be ordered to do 120 to 240 hours of community service on base, (if convicted or you plead guilty) so prepare for that, too.
Your Tricare won't be impacted, so there is that small blessing.
Going forward, please don't steal anything from anyone, it is far more costly than avoiding paying for whatever the shiny trinket would have cost you!