Transmission and braking noise Agila B 1.2 Built 2008

Hello everybody, for 4 weeks I have my little Agila and it is really great. The circuit seems to me however quite angular and often hooks. The gearbox makes noises when I let the clutch come (in the upper area). It sounds as if a wheel continues/turns. On the highway I have a loud, roaring noise when braking from higher speed at the front. When the brake is released it is gone. At lower speeds it does not occur. Can someone write to me If that’s normal with an Opel. Had 12 years Ford and 12 years BMW, this is my first Opel. Maybe it’s typical of Agila and I’m smiled when I go to the workshop with it. I’m grateful for every tip.