I don’t know about your specific use case, but sometimes, app not installed via play store don’t like it. You could try to install it via play store and see if that works.

Which Europeans need WhatsApp?

As other said, arch may not be for you. But I would recommend looking at KDE Neon too, it’s Debian based, with KDE as desktop environment, which is nice coming from windows. Whenever you encounter installation instructions about ubuntu, you can do the same on it, when with Fedora or arch you’ll be left alone figuring out how to install your stuff.

And my biggest advice is: take notes of what you do on your computer. EG, how did you install x our y software (Flatpak, command line, .deb package etc), which commands or software where useful for X problem. It will help you troubleshoot later or uninstall things you don’t remember his you installed them first, basically learn how linux works.