I'm on post realease probastion. Will that minor shoplifting charge send me back to prison or will they give me another chance

It's totally the Judge's choice. I do know that Walmart is a tough store. They do not drop charges, they do not argue for leniency.

If probation didn't "teach" you anything it's possible the Judge will decide something more "severe" is required.

What do you think would make a lasting impression on you?

I hope you're asking this question BEFORE committing the crime. Stealing is stealing regardless how minor it may seem to you. If you are violating probation, the result is usually to do the time since you apparently didn't learn the lesson.