As embarrassing as it probably is, I sometimes have difficulty talking "guns" with non-gunny people. (Sigh...and even a lot of casual shooters, too.) It takes effort to turn off the layers of expected fore-knowledge, technical speak, and rigid correctness and have a conversation that accomplishes something useful.
The best way I've found, for guns or any other techy field, is to listen more than talk and ask lots of questions to try and figure out the simplest answers that the person really needs.
"What do you want to shoot?"
"Do you know much about shooting and firearms?"
"Do you know where you might look at guns?"
"Do you know of a place near you to shoot?"
If pressed for specifics, common .22s are the safest bets, (and yeah, yeah...the ammo's still cheaper than almost anything else).
If they just want "TO SHOOT", a surprising and unexpected great idea is to see if there's a shotgun/sporting clays range around them. Those places usually have instructors who do a fabulous job teaching new shooters. Yeah, it isn't tactical, but it is huge fun, and quite safe, and a very non-threatening environment. I got that idea when I found out that a lot of big resorts have clays ranges now, and tons of folks on business trips or vacations (even
CRUISES!) will take a few lessons with the local instructors, just like it was golf or skiing.
Try to avoid correcting more than a couple of their worst misconceptions or gross misunderstandings about guns in one conversation. They'll probably get caliber wrong, tell you about how this or that isn't (or needs to be) "registered," probably tell you lots of things they've heard that are just dumber than a box of hammers. Let most of it go. Give them a couple of nuggets of really useful information, and assume that the rest will come in time.