Probably a troll but Federal law does not prevent an individual from making a firearm for their own use. My state does not but yours might.
You cannot make any weapon considered "NFA" which covers machine guns, silencers, short barreled rifles, short barrelled shotguns, some types of smooth bore pistol and other weapons. You are the only one that can follow the law. If it's confusing you might want to take the time to learn it or get it changed.
Semi auto pistols, rifles and revolvers can be made with rifled barrels. Shotguns that are not 'short barrelled' can also be made. Check your states laws on this. Some states laws are not kind to you if you try this even if the feds don't yet have a law prohibiting it.
Most people buy a kit of parts. I have an AK and 1919 kit. You will need to replace several parts to make it semi-auto and you have to replace the right number of American made parts to follow federal importation laws.
Then you need an 80 percent receiver. Disassemble the kit and sell off the parts you're replacing, do the machining on the 80% receiver to 100%, machine any other parts as required and then assemble the firearm. There are several things you will need to check to make a safe firearm, if you don't you'll be endangering yourself and others and liable for that oversight.
Know that this firearm is for you, while you may be able to sell it there are some restrictions.