Ответ:

1) I want a guitar but I don't have money. I should save money.

2) It's Mother Day on Sunday. We should buy flowers.

3) She wants to be healthy. She shouldn't eat fast food.

4) It's 11 p.m. and I'm tired. You should go to bed.

5) Karol wants to come to the party he's ill. We shouldn't invite him

6) They are going to be late. They should phone their parents.