Hello everybody i have a small question when trying to replace my radio I saw these 3 wires were loose do you guys/girls know what they are for?

That white wire and these 2 with the blue and white connector

Thanks in advance

 

The green white wire in the small white connector is your antenna booster wire. You will need to connect an accessory wire to it else your radio reception won't work.
For most aftermarket installs you will only need the one biggest white connector. I just finished installing my third aftermarket headunit. In my case I have amps and subs for sound so the only wires connected to the car side are yellow for 12v constant, red for accessory, orange for illumination which are all in the biggest connector and then the green white wire I mentioned.
Ground of course goes to chassis. I don't have steering wheel controls and the stuff so all other connectors were unused