I’m Stuck on the OS X Utilities

Hi. I’ve had a MacBook pro since 2014. I wanted a factory reset so I googled it and I did the process.

The video said to delete something from the disk utility, I didn’t have the same name as the one video had on it. So I clicked the one that was the same place and after the video said too click “ Reinstall macOS “ but I had “ Reinstall OS X” so I tried to reinstall it but it said that the “ OS X Base System” was locked. I don’t know what to do...I googled”how to get off reset mode on MacBook Pro” and I did that process but it keeps bringing me back to the “OS X Utilities “. Any tips? Or any advice on what do to? I’m not sure how to work it..