White lines or rings around foreskin, i can retract and there's no tightness, i've never had sex but i do masterbate frequently. what can it be? cure?

Here are some...: What you saw and concerned on glans penis could be just normal for you as long as not bothering you. In fact, an extreme of benign skin change of glans penis is called scrotal glans penis (glans penis plicatum). Nonetheless, without a direct look at, it's hard to give right impression. So, as needed, seek evaluation & counseling.