Users Request System PHP

I have a web app that I must create A system in which users send requests for other users in order to exchange INFORMATION If they accept as requests.

1 - User Profile screen:

2 - If the user clicks on " NETWORK " displays the following message:

YES OR NO

3 - If clicked " Yes " is sent the request to the corresponding user

4 - If user accept, display contact Informations:

Someone recommended a tutorial so I can make this system in PHP + MySQL ?

Thanks guys!