Hi i need good advice...?

you don't have any disease nor condition dear... stop worrying, you're a normal male with a healthy virility, that's why you get all those erections :) and speaking as a female, your tight foreskin is a blessing, because it protects the sensitivity and keeps your tip lubricated for girls... leave it alone and don't force it, ever, is perfect as it is... kisses xoxo

If you are a virgin you dont have an STI. Smegma is normal secretion of the human body, if that's why you were saying that. And these "at-the-drop-of-hat" erections are normal at your age.

As for your tight foreskin, the ability to retract is something that tends to gradually develop throughout puberty. It is typical for guys to only achieve full retractability of the foreskin whilst erect once they are in their late teens. You just haven't reached that stage yet. Some simple foreskin stretching exercises can help you though...

Whilst erect, simply tease the foreskin back as far as it will go without hurting and hold it there. Don't force it back; stop when it's visibly taut. Do this frequently and as time goes by you should find that it goes further and further back.

Just be patient. It may take weeks or months of doing this before you're fully there so be careful. You don't wanna go too far too soon cos your foreskin could tear or become inflamed and cause problems. I wouldn't recommend pulling your foreskin back while flaccid either — you really have no reason to be doing that and you could run into trouble. Just take things easy and you'll get there.

Its not an STD but go to the doctor, you may need circumcision.

Most likely you do not have an STD because you are virgin. Unless you have had oral sex or shared needles it is VERY unlikely. And random erections are just a part of puberty. If you still want to get checked u can go to free clinics in you area or planned parenthood. Sound like you have nothing to worry about though. Goodluck :)