penggunaan yang tepat dari could and should ?

I could make a cake for Andy's birthday
I couldn't dance today
Could I drink a lemonade?

I should clean up my room before I go to the dining room
I shouldn't play with fire
Should I take a book there?

I wish I could fly
Could you please move a little bit?
If i weren't busy, i could come to the party

you should study hard
she should pay more attention

could and should are both followed by infinitive 

semoga membantu :)