Hi
I'm new to all this so I apologise.
How do I actually download from it?
When someone posts a link and password what do I do?

Thanks in advance

Click the MEGA link.

Click the "Download to your computer" button.

Once the compressed file is downloaded, open it in 7-Zip/Winrar/Keka/whatever program you want to unpack the files.

If the file is password-protected, then it will prompt you to input it. Just copy and paste it from the thread where you got it.