What do you recommend for a new gun owner?
Guns are tools. Different tools are needed for different jobs. What are you attempting to accomplish?
You wouldn't use a snub nose revolver to go deer hunting. You wouldn't use a deer rifle as a conceal carry weapon.
Conceal carry
1) Glock 42/43/26
2) Ruger LCP / LCP Max
3) Snub nose revolver
4) Sig P365 or Springfield Hellcat 9mm
5) Smith Shield
Home Defense primary
1) Home defense should almost always be primary supported with a long gun.
2) EVERY home defense weapon that is deployed for home defense should absolutely positively have a weapon light mounted to it if possible. Most modern firearms have a way to mount a weapon light.
3) A semi automatic rifle or high quality (read expensive) semi-automatic shotgun is ideal here. Not a fan of pump shotguns for novices, as they are experts weapons and require a large amount of training to become proficient.
4) I really like pistol caliber carbines like the Ruger PC carbine, Beretta CX4 storm carbine, or CZ Scorpion carbine and recommend them to my students.
5) The AR15 (or similar magazine fed carbine in an intermediate cartridge) is probably the best home defense weapon that money can buy. It has a lot of firepower, with a lot of noise, with reduced penetration risk to innocent bystanders. If you wanted the BEST home defense weapon, you'd be looking at an AR15 style rifle.
Home Defense backup
1) Full size pistol, 9mm, with a large capacity magazine. Like a Glock 17, or Sig P320 or similar modern polymer pistol. Full size. No need for compact for home defense.
1a) If you live in a non free state with ten round limits, then get a 45ACP pistol with a ten round magazine. I really like the Smith M&P45.
2) Should have a rail on the bottom with a rail mounted light.
As it relates to home defense, the pistol is a backup weapon. It is not a primary weapon. If I hear glass breaking down stairs and voices, I would not grab a Glock 17. I would grab a long gun.
Me personally, I have made the case that a "gun owner" that uses guns for defensive purposes, would own at least 3 guns. A smallish carry gun, a full size service size pistol, and a long gun. If you hunt, add in a few more for hunting purposes. If you are just starting out, and need to start "somewhere", I would start with a carry pistol. Its the most useful and will get the most use, assuming you conceal carry. Then as money allows, get a long gun for home defense, and then a full size pistol.