Congratulations! My advice would be
> Download the user guide from the Mint website and read it.
> Start using the programs you will use most and read their help. If you need LibreOffice, that has free ebooks available.
> Have a look at the configuration tools available from the menu, to see what they do and if you would like anything changed.
> Never be afraid to experiment, but never change a file without making a backup.
> Have a look at the software available, either just in the software installer or, to find suggestions, at
https://linuxappfinder.com/