What can I do to make my penis bigger?
The only thing that affects your penis size is the genes you inherited from your parents. Since you can't change your genes, you can't alter the size of your anatomy. There are thousands of products being sold that claim to make your penis bigger, but the fact is that none of them work.
A few cause you to have a semi-erection, where your penis inflates just a bit to expand in size, but not enough to be hard. This gives the appearance of being bigger, but it doesn't last. Besides, your penis constantly varies in size in response to temperature anyway.
Some of the other products stretch (or in case of surgeries, cut) the ligament that holds your penis at an upward angle. Since there is no restraint, your penis hangs lower and appears to be longer. However, when you have an erection your penis remains pointing downward. When you get married, this might make sex a bit awkward.
However, 99% of the stuff being sold does nothing. They are only after your money. They count on the fact that you won't go after them for a refund because that would involve publicly stating in a court that you bought a product to make your penis bigger and it didn't work. To prove your case you would have to prove how big your penis was before and after using the product. Who would want to make public such detailed information about the private area of your body?
Remember what Jesus said, "And which of you by worrying can add one cubit to his stature? If you then are not able to do the least, why are you anxious for the rest?" (Luke 12:25-26). Instead of wishing that God had given us something else -- greater height, bigger penis, different color hair, or whatever -- we need to accept ourselves for who we are and not who we wish were were. Life is short. Enjoy the life and the body God has given you.