There’s no answer anyone can give you here because laws and regulations vary not only on the state level, but local as well. Essentially you would have to check with your local authorities or the game commission to find out what your state’s and local regulations are.
Maybe you would want to read this article to find out what you’re potentially dealing with concerning the event you would happen to get bitten, and even best case scenarios suck, are extremely painful and are very expensive. The site tells you what to do, and what laws pertaining to venomous animals are on a federal level.
I used to keep venomous snakes as pets myself, usually ones I would catch in the mountains behind my house. Personally I didn’t see the appeal of keeping snakes on hand that I couldn’t safely hold, so I eventually released them back into the wild. I had decided to stick with snakes I could hold.
If you are going to acquire a venomous snake I would avoid black mambas at all costs. They’re among the most wiry and nervous snakes that exist, and their bites are almost always fatal despite not being in the top 10 venomous snake group. Even zookeepers and experienced snake handlers fear these snakes, and many zookeepers actually get rid of them because black mambas are that dangerous.
Personally I’d go with a coral snake or other more docile venomous snake. Coral snakes are highly venomous, but their venom rarely penetrates into the skin, or at high enough doses to be dangerous most of the time. Copperheads don’t have powerful venom, but it’s still a hemotoxin, and thus is still a very painful bite that can cause permanent skin and muscle damage. Copperheads are more aggressive when compared to many other snakes too, though they prefer to avoid conflict against bigger foes and flee when they can.