Most gun owners buy a gun and never intend to carry it. Including myself when I was young. I changed my mind after a co-worker had been shot in the belly after giving up her purse to a mugger. Nobody knows if the mugger did it out of curiosity, anger, or if he intended to eliminate a witness. I got a WA conceal permit after that and began carrying.
Here's a list of my recommended firearms for a first time gun-owner so that you have a handgun that can become your carry gun in the future if you ever choose to go that route. You can always get a big heavy range pistol as your second firearm, but a good carry gun covers all bases in case you want to carry one, two, five years from now or never carry at all in your lifetime.
Springfield Hellcat OSP; smallest 9mm double stack package in the world, highly accurate, but has harsh recoil on the web of your hand. Buying a aftermarket or separate hellcat PRO long slide with porting or compensator can reduce some of that harsh recoil. Light defensive ammo will make a huge recoil reduction. Always secures top places in thousand or more rounds fired tests.
Sig P365 optic ready; America's favorite and most purchased handgun in 2023. The micro would be the best general purpose, but some people are willing to sacrifice conceal carrying features and scale up a 365 to the larger variants. It has light recoil, has a 380 variant, and is completely modular. It's a tiny bit wider, heavier, and doesn't have as good of a size to capacity ratio of the hellcat
Glock 43x; Has a long slide variant. Everyone likes glock. More prone to limp-wrist jams if you have a beginner's loose grip
Stoeger STR 9MC deluxe; Nearly identical to size measurements of the hellcat and is extremely cheap. But it is not very durable at all and you can expect it to have a short firing lifespan of a finite amount of rounds.
Ruger max 380; good for sweatpants no-belt pocket carry because it's the lightest double stack ever made at 11 ounces. 380 is a problem for being on the bare-minimum of defense but nowadays you can choose high-end, better performing self defense ammo. It would need to be range-tested because ruger pistols do jam often that aren't quality inspected.
Shotgun or Rifle?
As a WA state resident you are close to entirely confined to shotgun only. Shotguns are a better choice for home defense when loaded with #4 buckshot for minimum drywall penetration, or larger for more damage. Each pellet does serious damage similar to a fmj pistol round.
Any mossberg pump-action depending on your budget: 88, 500, 590, 590a1 series in order of price. The 88 is extremely cheap.
Beretta semi-autos are amazing but tend to be in the $1000+ range. They have the A300, A400, A1301 series
For shotguns you should maximize the carrying tube as home intruders rarely arrive alone. Minimum barrel length is 18.5' legally. Mossberg shockwaves shorties are banned in WA.
Rifles
.223 5.56 can have some drywall stopping abilities because of their light weight bullet. They do penetrate more than #4 buck. Their greatest advantage is longer ranges, accuracy, recoil, and capacity. For Washington defense, this isn't much of an option. The following is reserved for non-WA residents.
7.62x39 caliber rifle or braced pistol (unless the braces becomes banned due to anti-gun measures in future)
any .223 5.56 caliber rifle or braced pistol for extended ranges like in sub-rural areas.
There's two types of rifles that seem to be legal to purchase in WA: M1 Garand and ruger mini rancher variants? Attorney General will not make it clear and prefers to keep anti-gun laws as vague as possible to apply.