Update consistently since it’s a rolling release distro, once a week should do it.
sudo pacman -Syu
You can also use
yay
But note yay will also update your AUR packages.
If you can, install software from the arch repo. If necessary, additional software can be found in the AUR. Don’t download and install software from random site or from git. Flatpak work but most packages can be found on the AUR anyways.
I would learn essential package management on pacman first. Like updating system, searching packages, etc.
If you can avoid Nvidia, avoid it. It’s just a pain especially hybrid cards.
Check the forum. Most problems can actually be fixed and you get help. If seeking help, make sure to post hardware infos, systems logs etc. You can click the top right help button and select log tool for more infos.
Couple of useful links:
- Don’t hard reboot. Instead check this [Tip] Enable Magic SysRq Key (REISUB)
- Package management links from @Kresimir and useful links about AUR
KDE Plasma fresh other distro reinstall: 'Appstore' and non-aur repo doesnt work - #10 by Kresimir
Welcome to this community and forum! 
Edit: i3wm is the best for sure 