have no idea what "Recovery" is?
Recovery mode is basically booting up your Mac from hardware and built-in memory, independent of your boot up drive, so that you can perform operations like Disk Utility and software installation and updates independent of the status and condition of your startup drive.
Anyway, without risking anything, I suggest you try it just to get a feel for what it is like. Once you are in Recovery, just look through the different parts of the menu just to familiarize yourself with the process. One thing you will need is internet connection if you are going to download files. As I said, you don’t have to erase anything with Disk Utility, or install updates, if you don’t feel at ease with it.
So, in order to enter Recovery, shut down or restart the Mac and immediately hold down the keys, command-R. Keep holding the keys down until the Recovery screen comes up.