php not installed on my server

Hi I am a total novice on computers and got lost after the first line in the 5 min set up.
I undid the zip but where do you upload it to ?
I clicked on the link in the 2nd line and got this.

WordPress requires that your web server is running PHP. Your server does not have PHP installed, or PHP is turned off.

I think this is the stuff for people who know how to use computers.
When you answer please talk to a very old man who has drunk 2 bottles off wine and wet himself or a 3 yr old who is having a tantrum.
I did do a search and looked at other posts on this subject but was totally lost.
Sorry to bother you but I thought it might be worth a try.
Thank You.