Get321healthy,
It is possible to get a prosthetic testicle placed. It can usually be done as an office procedure.
As to the foreskin, in some men, it just happens. The best thing to do first is to try to gently stretch it. You can do that with the help of some lubrincant, and gradually, gently stretch it over time.
This usually does the trick. However, if it becomes a big problem, about the only thing that can be done is a circumsection. But, that is rarely needed, as stretching usually works very well.
Good luck.