Think of linux as desktop android… That’s probably the best advice I can give you. Depending on which distro you choose, they’ll have different app stores. GNOME Software for some, discover (yes, that’s the name of the program) for others, Pop!Shop for Pop!OS. As for managing apps - avoid installing snaps. Other than that, don’t worry about it.
Pretty much all cloud providers are supported on linux, most of them just don’t have bespoke apps and get added directly to your file manager. Some distros have a step during the initial setup, where you can log into accounts and what not, which should setup stuff like OneDrive automatically. And if not, i don’t think setting them up manually is too hard.
Do not install/uninstall stuff from the terminal. Most self-respecting user friendly distros have an app store which does all the things for you. Installing things from the terminal/the internet should be a last resort, only if the thing you want to install is not available anywhere else.
As for my distro recommendations… try Fedora KDE or Linux Mint.