How to install Radiant Floor myself
The reason you were told to talk to a PRO is because it can be a complicated setup.
You need a source of hot water generation, separate from your domestic water system.
This could be another electric water heater, a gas heater or even a boiler.
You'll need a mixing valve and a pressure tank.
Without a basic understanding, you are going to be hard pressed to find someone able to school you from ground zero.
An electric based radiant heat system is different, and IMHO easier to install. You may be able to find a kit or source online and lay it down yourself. You'd still need an electrician to make the final connections.