The red one looks like an aerial connector. Without being there, it could be GPS or DAB. Vehicle may be wired for this, although exsting head unit may not use it. Presence of wiring does not indicate the respective aerial is fitted, so the other end may also be loose.
The second one looks like steering wheel controls connector, may be specific to a particular radio brand, again, maybe not fitted to this vehicle. Adding a wheel with radio controls may not work, so try not to get excited.