Creating a shopping cart in Unity scripts problems

Hi im trying 2 learn how to make my wery first shop application in unity. Gui work is done already but i have no idea where to star with scripting it... im a totaly noob in that but i realy want to learn scripting basics. As for now i cant find that kind of tutorials, so i decided toask here in hope i will get some guidence. More informations : -I need 2 have 2 bascets.(1 quick viev for cusstomer and another normal page bascet. - all buttons are set for now. for rly i need some clues, from where to start and what target should I get

Sorry for my poor English.

Im adding some screens for u 2 know how it looks so u can understand of what im talking abut.