Cracks underside of penis head?

Hi im 14 and im just checking is it normal to have crascks undearneath the penis head like on it but at the obottom like the underside theyre not dryed out or nothing cos when theyre stretched theyre normal and on my penis head their is alot of like wrinkes/lines but again when stretcher theyre normal although when they are strectehd you can barely see white lines on my penis head is this normal? im not sexually active too.