You ask for CLI, as GUI to search for apps use octopi, but for updates and install use the terminal.
Start reading and searching here in the forum 
and the garuda wiki.
Make sure you have done the following before you post:
- Search the web and forums
- Read How to search for solutions the right way | Garuda Linux wiki
- Read FAQ and Tutorials Table of Contents
Issue still unresolved? Then:
- ONE issue per topic.