Ah yes you have definitely come to the right place.
There's two, depending on your resources. If you have access to nitrates, like most Americans do, you can probably get sulphuric acid too. Salt metathesis reactions can be used to get hydrochloric and nitric acid from a salt - obviously, chloride and nitrate salts - by mixing it with sulphuric acid.
The sulphuric acid's SO4 ion switches places with the Cl or NO3 ion of the salt, producing a mixture. It's best to then distil that acid away in manageable quantities - hence, what kind of equipment can you actually use? If you don't have a distiller, there's still a huge difference in boiling points between sulphuric and HCl/HNO3, so you can still distil them - just make sure it's airtight.
Depending on how DIY you go - if you have the right skillset, you could probably go right to the beginning. That takes welding, forging, metalworking and glassblowing skills - but in its essence, you can make most shit from seawater, air and plants if you have enough energy.
>Americanisms
My great granddad fought at the Somme before he was old enough to drink. If you can expect people to breath mustard gas, then you can trust them to make it too.