Cat help lol

Hi ! So I just bout a little cat today he's 2 years of age and I need some advice ! His previous owners don't have time for him no more and when I saw him advertised I just had this feeling that I have to get him. As he's obviously lived in his previous owners house for his little life I'm worried he's going to try and run back! So how long do you keep them indoors before letting them out again? And is it true you have to butter their feet ? Sorry if its a dumb question I just keep getting mixed answers off people, thanks