1) Ask for some bona fides (eBay, Facebook marketplace, etc....i.e. feedback). No online presence is no invite home. If google dosen’t know you, you’re likely not real these days.
2) There’s not much difference between a garage in you house and a living room.
3) Get traceable info on him (phone, maybe even adress) before meeting
I’ve only been burned once, guy got agressive when I wouldn’t lower price, I walked him out thru the garage. Ended up calling cops when he threatened me after I discovered his girl friend was trying to buy the same turntable via texts).
These days I meet at the town center (police/fire/library) unless I’ve done the above as well as really hit it off online/on phone. Cuts both ways since if I’m selling something (big, old guy) to a young woman, so police department parking lot can be comforting.