Let us/ shall we

1. Let us celebrate your birthday in a grand manner.
2. Let us do our homework now.
3. Let us go for a walk.
4. Let us buy some apples.
5. Let us have our dinner now.
6. Shall we  go to the park?
7. Shall we visit our grandparents this evening?
8. Shall we recite the poem now?
9. Shall we go to the park?
10. Let us play chess now.
11.