physical relation with ones girlfriend

According to some religions, it's bad to have a physical relationship before marriage. If you belong to a church, you should ask a trusted church member or official. If you're not religious, then there's nothing really "wrong" about it. You just need to make sure she definitely wants to do it and be able to maturely discuss issues such as infections and possibly pregnancy. It's romantic to just spontaneously get physical, but in the beginning of a relationship you should be careful.