Well that depends. You testicles will get about to the size of an egg only longer. You sack will vary in size. .. shrink in the cold.. .. and sag when its warm. This is to keep the sperm at the right temp.
The size of a large egg is the usual size.
It’s probably not the definitive answer you want, but, it depends. I’m assuming you’re experiencing puberty. It’s quite possible to have large testes and a small penis, or a large penis and small testes, or average sized penis and testes, or any combination thereof. Mine are the size of USDA Large eggs, so you can reasonably expect to have testes around that size (perhaps larger or smaller) when they are fully developed.