Amazon has an app store for Android, slideme is another, Samsung has an app store, there are others of you search Bing or ddg. Then there simply sideloading where a website gives you an apk and you install it like you would on a computer. Click and install and you're off to the races.

apkmirror.com brother, I have been using for nearly a decade with zero issues. Go for the latest/most recent versions of apps (apk's), bypass google and its fascist playstore. You can turn that shit off on your phone in app settings too.