Renault Grand Espace Initiale Radio Trouble

Hi I am in need of help. I recently have baught a renault grand espace initiale 2.2 dci 54reg. However I couldn't get the radio working. I found a cd changer in the boot. But I can't find the radio. Someone told me the radio is kept under the passenger footwell. So I opened the flap to find an empty space and what seems to be audio connectors. So I baught a radio head unit thinking it will go in the gap but it seems to big and the connections are wrong.
Can someone please brake down on what I need and how I can my music/radio playing please.
You help is appreciated

Renault Grand Espace Initiale Radio Trouble