Each and every user and use case is different - there is no one-size-fits-all.
That said you should take a look at the Tutorials section - there is a wealth of documentation written by members …
To mention a few …
- [HowTo] Install Apache, MariaDB (Mysql), PHP (LAMP)
- [HowTo] Reach a minimal system
- [HowTo] Find system information
- [root tip] [How To] Samba Server From Scratch
- [root tip] [How To] systemd mount unit samples
- [root tip] [How To] Update Manjaro the smart way
- [Need-To-Know] About Manjaro and AUR
- [root tip] [HowTo] Check if your AUR build scripts have been updated
- [root tip] [How To] Disable write cache for USB storage devices
The Manjaro wiki
The Arch mother wiki