So I have stolen small items such as football cards a little while back, but I am now I realize it was just stupid. I never got caught or questioned by walmart at all? Can I still apply and get a job there? Or will they be able to recognize me somehow? I have no further intentions of shoplifting anymore.

If you didn't get arrested, or even confronted, then how would they know you stole from them? Walmart has pretty strict hiring practices, at least were I live. My friend who works there had three interviews, a questionnaire, and more. So, when they ask you if you've ever stolen anything, will you be honest? When they ask what you would do if you saw a fellow employee stealing, will you lie?