im daunted and need help

hi so im currently using windows 10 and in december i think windows 10 support will be no more

and my laptop is so old it cant run windows 11 so i need NEED help for the basics of linux

im either planning on linux mint or sum arch based distro but i have 2 questions

1. is there a difference between arch and debian

2. can you customize linux mint? 

and 3. what terminal commands almost every linux user should use?