I know of an absolutely fantastic USA vendor, but its on the darknet.
If you're not familiar, at minimum you're going to at least need the Tor Browser and a PGP keychain (gpgtools.org). You'll have to understand how PGP encryptions work.
You can find more info about this on reddit r/darknet and the DNM Buyers Guide (
https://drive.google.com/file/d/1yogmGs_Hau3NAOnzQQmtTuwTJ8yR77g7/view). The DNM Guide will recommend you install the Tails OS booted from a USB stick, but IME unless you are super paranoid about opsec you'll be OK with just the TOR browser and PGP. The Guide also has a PGP section.
Assuming you understand the minimum DM me and I can point you to the market and vendor. I won't give you any direct links since you should most definitely not trust me, but I'll tell you what to do.