Yellow substance leaking from penis. never had sex before. no trouble or burning when urinating. not circumcised. small cut on skin. is this bad?

Likely semen: Semen is constantly produced although usually only escapes with a sexual climax or as wet dream fluid. Yellow color is primarily from small amount of urine mixed with semen. Hope you have normal forceful urinary stream because presence of a urethral stricture (narrowing) could account for semen leaking. You can have a stricture without any burning, just takes long time to empty bladder.