My question involves criminal law for the state of: LILBURN, GEORGIA.

I was stopped walking out the doors and some guy came behind and asked me to follow him they took me to a room and they told me to put everything i had on a table after that they asked me for my ID and they told me to label some paper. I didn't had my id with me so they called the police and the came they verified all my information and took me to the police station and took my finger prints after that they gave me a court date and they told me that for stealing $40 dollars i had to pay more than that and i feel so stupid for what i did and know i cant be near Walmart property nor parking lots. (is this gonna affect anything in college? and also its my first time getting arrested my record was clean until that stupid day. what should i do now? whats gonna happen with my record? how long does THE charge stay on my record? do i need an attorney ?