My one testes is larger than the other and so is the epididymis and the veins feel slightly bigger than the ones on the other side however i dont have any pain or lumps. if i am going through puberty is it normal?

Pl see a Urologist to exclude any thing worrisome.

It is totally normal for one side to grow faster and thus be larger than the other side during puberty. That is actually the normal way it happens - it's actually unusual for them to be of equal size until completely through with puberty, and then they aren't always the same size. It's the same as with girls breasts - one is almost always larger/fuller than the other one. Not to worry!