Its a matter of trust and choice, i've never purchased from a newbie, not saying its not done, but having purchased well over hundreds of gats from private individuals on many websites, its usually been accomplished via a known individual who has info, referral info.
Only had one issue in all this time of buying and an extra fella came out of no where, i assumed he was a threat and was prepared, but was a guy trying to be funny, but didnt' grin when he realized i had a gat i my hand, at my side, boys learned real quick, buying a gun can be an enjoyable moment, just not a surprising one. all went well, and in the future bought thru this one fella many times.
Asking all the right questions prior to meet, and having a dialog via phone, text, can assist in ones comfortable level, and of course public location, i never worried about location as long as it was open and public, who cares if some hoplapob gets freaked out, its their problem not yours, of course just my opinion and don't forget basic requirements, Az. citizen, with ID proof, ect.
good luck, privates sales are the greatest if one can achieve his'/her goals.
Rj