Truthfully, documentation is your friend, read it and interpret it as best as you can.

and I want to be able to download "app" "installers" like you do with PC or MacOS

Linux systems use Repositories to install “packages”, these packages are pieces of software that are either small or relatively large, for example the Linux kernel itself is a pre-installed package on every Linux distro.

Packages can sometimes depend on other packages to function properly, this is what we call “dependencies”, if you’re missing a dependency that a package requires it will likely fail to execute.

Lately we’ve been seeing packages like Flatpak and Snap enter the Linux ecosystem, their goal is to make Linux easy for newcomers such as yourself where you don’t have to worry about dependencies and you just click the “install” button for a package and be done with it however, in the background Flatpaks and Snaps put that package in a “virtualized container” with the already required dependencies installed, which works great for newcomers but most Linux veterans will prefer native packages as they’re easier to troubleshoot and requires less overhead (resources) from the computer.

Circling back, it is important to note the top 3 distributions available. Debian, Fedora and Arch the majority of distros out there base themselves off of one of these 3, Ubuntu is based off of Debian, SteamOS is based off of Arch and Nobara is based of off Fedora, you get the idea, personally I’m a Debian user and suggest it only if you want the ”raw” Linux experience otherwise I would suggest Linux Mint and or Kubuntu for beginners who’re just learning.