It's not as easy to become a broker on the OTC market since it's not a 'public' market. If you ask where and how to find buyers and sellers, it's perhaps because you have no demands yourself, so no use to have a service because it is based on supply and demand. Don't get it wrong, I say this because you are probably wasting your time.
Additionally, you surely need a state license and not even talking to register a company number because as you can guess, nobody would trust a random individual to deal with money. Especially in the OTC market which usually deals with a high amount of money.
You also need some knowledge in the finance industry and accounting. It's not only because you know the crypto world that you can run such a service. You have to build a network, you have to abide by the laws, verify IDs, source of funds, net worth, market analysis...
In other words: running a company.
No, it's unrelated to what you're looking for