Don't worry about the terminal until or unless you have something to do that needs it, then follow a guide

Incidentally if a guide tells you to run a program in terminal, you can check what that program is supposed to do

• man command (eg. man mount) gives you the manual, if it has a manual
• command -h or --help gives you the command's help page - pipe it through "less" if it's more than a single screen eg: ls -h | less