There are a few big differences when it comes to the package management. Pacman, AUR, and rolling release are some of the largest differences. Y

ou will want to familiarize yourself with some of the most common commands for pacman such as Syu, S, Rsn, Si and such. If use the default shell for Cachy (fish), then tab completion should help.

As for the AUR, that is where you will want to install things that aren't part of the base repo. Keep in mind some stiff is community packaged, so you might not get the support you would expect on Ubuntu.

Finally, Cachy is a rolling release so every time you install a new package, you need to also update your system. In the past rolling distros have been more unstable due to the release schedule, but things don't break too much now. Cachy helps avoid breakage by having snapper which will let you boot into your system with older packages from your boot loader.