First Offense Petty Theft, I have a couple questions regarding the matter

I got caught stealing about $51 from a store in Maryland earlier today. They took me to an upper office, took my picture, took a picture of the merchandise, told me I was banned from all stores across the country and told me that I would be receiving a court summons later in the mail at some point in time. They made me sign two documents, one was the one where I was banned from all chains across the country, and the other one was one that said that I took the merchandise with the intent to shoplift it. Looking back now, I guess it wasn't the wisest choice to sign that second one on the spot, but I was scared and I didn't think of the consequences of signing that document

I'm 18 right now, and I'm weeks away from sending my college/scholarship acceptance. I really don't know what to do right now. My family really isn't in the financial position to hire a private lawyer, so I guess I'll be going with a public defender. I'm currently looking everywhere on the internet on the possible consequences for a first time offender, with my main goal being to keep my record clean. I'm willing to do any number of community service hours to do so, along with attending any programs needed, as long as it doesn't go onto my record. I have a couple questions regarding the matter.

1. How likely would I be able to keep my record, as an first offender adult, clean?

2. Should I contact the office of the public defender now? If not, when should I?

3. Would the news of this incident be given to my highschool/prospective college/internship, even if I haven't gone to court yet?

Any other advice on how to proceed from here on would be greatly appreciated.