If you are looking for a simple, basic handgun for protection, I'd look at a few NIB(new in box) .38/.357magnum stainless steel DA or DA only revolvers.
The limited ed Ruger Talo 4" barrel .357magnum is a great defense gun. Other top brands include the S&W 686+ 3" barrel or the 4" L frame. The Ruger GP100 .357magnum or the DA only SP101 snub could do the task.
For protection, I'd use factory made .38spl +P or +P+ rounds. Magnums are top rated but the blast, muzzle flash & recoil may cause major problems.
Good .38spl +P rounds include the Speer Gold Dot 135gr JHP +P, the Corbon DPX, the Buffalo Bore 158gr lead SWC-HP +P, or the Ranger T .38spl +P load.
for gun care/cleaning products. A CLP like Ballistol, Gunzilla or LPX will maintain your firearm.
Learn the local gun & use of force laws. Your actions will be under investigation after a critical incident.
Be ready to protect yourself & use good judgement.
ps: a Bore-Store bag is a good way to protect your handgun. It's easy to use & prevents scuffs, rust, nicks. I owned a bag for over 20 years.