>>510591663
1): Glock 19 or 17, Gen 4/5. First gun. Ignore anyone who says anything else, this is the universal default starting for a reason, everyone eventually gravitates back to it.
After that,
2): S&W Bodyguard 2.0. That's the current conceal carry META.
3): Mossberg 590s. Shotguns are good. 00 has roughly the same diameter as 9mm, you want Hornady Black 12ga or Federal Flitecontrol. Each shell would be like shooting a .380 eight to nine times.
4) AR15, any. Go for $900-$1,200 range.
After, can buy whatever you want.