The first gun I place in a new shooters hands; Henry Lever Action H001 in 22 long rifle. Smooth action, Simple operation, Easy to make safe. Inexpensive, reliable, and pleasant to look at (not intimidating). Ambidextrous. That would be my advice to a brand new gun owner. Next in line would be a Ruger 10/22 for people familiar with guns, have shot guns, but do not own guns yet. I would not recommmend shotguns, pistols, centerfire rifles, or revolvers as a first gun for previously non-gun folks. Keep it simple and familiar. Lever action is almost a part of everyones DNA. Hand them the lever action rifle. Train them to open the bolt and close the bolt using the lever. Train them to open the bolt and leave it open. Every new shooter I have trained; even the anti-gunner types, have absolutely loved lever action firearms and learned them quickly. The easier, more fun, least painful, and simpler the introduction to firearms, the more likely the person will have a positive reaction. Without question the first caliber a new shooter tries should be .22 long rifle or less. A positive reaction for a new shooter; regardless of their voting preference, means a win for the 2nd Ammendment and all of us.