Can you check the following sentences for me, please?

1) Last year my brother and I went for a ride on our motorbikes (Can you also say: "I went for a motorbike ride with my brother?)
2) We were riding on a digged up road. (how can I say that the road was unsurfaced, dirt?)
3) All of a sudden my brother, who was before me, stopped because he had seen a pheasant crossing the street (or he stopped because I pheasant was crossing the street or he stopped to let a pheasant cross the road)
4)Unfortunately, I didn't manage to jam on my brakes and I smashed into my brother's motorbike
5) I broke my feet and part of my motorbike (I damaged my motorbike, too?)
6) My brother's motorbike went down a slope and landed in a river(?).
7) I was really frightened and I shudder (what are verbs can I use?) when I think about it.
9)I'd prefer you to go to the cinema rather than (go) to the restaurant.
10) I'd rather you drove to the mountains rather than go by bus.

Thank you for your help.

Most were fine just the way you wrote them. I would make the following changes.

2. We were riding on a dirt (or unsurfaced) road

3. All of a sudden, my brother, who was in front of me, stopped because he saw a pheasant crossing the road.

(A dirt road would usually not be called a street. Past tense (saw) is better. "Had seen" could imply seeing the pheasant earlier.)

5. I broke (both) my feet and also damaged my motorbike.
(Equating body parts and vehicle parts as objects of the same verb sounds a bit strange)

Sure! Here are the revised sentences, along with some alternative suggestions:

1) Last year, my brother and I went for a ride on our motorbikes. (Yes, you can also say, "I went for a motorbike ride with my brother.")

2) We were riding on an unsurfaced, dirt road. (You can describe the road as "undulating" if it had bumps, or "rough" if it was uneven.)

3) All of a sudden, my brother, who was ahead of me, stopped because he saw a pheasant crossing the road. (Alternatively, you can say, "he stopped to let a pheasant cross the road.")

4) Unfortunately, I couldn't manage to brake in time, and I crashed into my brother's motorbike.

5) I broke my feet and damaged a part of my motorbike.

6) My brother's motorbike went down a slope and ended up in a river.

7) I was really frightened and shudder when I think about it. (You can use other verbs such as "tremble," "quiver," or "shake" to describe the same feeling.)

8) There is no question with number 8. Let's move on to 9.

9) I'd prefer you to go to the cinema rather than the restaurant.

10) I'd prefer if you drove to the mountains instead of going by bus.

These revisions should make the sentences clearer and more grammatically correct.