How to add functionality to buttons

I'm new to php, and I'm doing a site manager, with it I want to manipulate the database, I'm listing the database's data and every bank item has three buttons to view; Edit, which will edit the name and Delete; but I do not know how to put function on them to change the item that is selected, more specifically I do not know how to pick the selected id. Help me with this project and deliver it on 02/262018.