My suggestion to you, is please oh please replace Manjaro with EndeavourOS. It does everything Manjaro does but better. The learning curve will still be the same.
pacman: EndeavourOS has yay installed by default, which is an AUR helper. It interacts with pacman and builds your packages for you. yay -S steam for instance calls up pacman and builds the steam package from the repo and takes some of the head scratching out of it. Very easy to use. A simple “yay” to update, no sudo needed, yay will ask for a sudo password when it needs it.
Shell selection: bash is fine, and bash is enabled by default in EndeavourOS.
But the real reason to use EndeavourOS, aside from having an arch based rolling release distro, is its community and support. An amazing forum, tons of documentation between EOS and arch itself, and fantastic wiki that guides you through various tools and utilities you may want to use.
It is a terminal centric distro, but you can easily install GUI tools for things you don’t want to do in the CLI.
I would even be down to correspond and help you out if need be. Manjaro looks cool when you’re in those early stages of outgrowing Ubuntu, but it’s not the distro you’re looking for, I promise.