If it’s just an interview you don’t have to be prepared to work. I had acrylics nails on at my interview as well as my onboarding and they just told me that I would have to get them off before training. You hair should be neat and clean however you would like to do it. As far as your record goes they will do a background check so if you feel that it may cause then to not want to hire you perhaps you could mention it but they will find out either way.