Welcome to the forum!!
You will need to give us a better explanation of what you want to do. If you want to enter commands, you need to open a terminal (it will be in your menus)---or you can usually get a terminal with ctrl-alt-F1
In a terminal, Linux commands are very similar to Unix, but there are some differences. You can try the ones you know---if you see something not working the way you're used to, then check the man page.