Do we need to assign the Story Points at the Story level or Task level ?

Hello Everyone, 

I would like to know the following and please provide your inputs.

a) Do we need to assign the Story Points at the Story level or Task level ?

Example : I have a main Story consists of 3 tasks and I have assigned story points to each task ( example : 1st Task - 2 SP ; 2nd Task - 3 SP ; 3rd Task - 2 SP).

Can I assign 7 Story Points to the main Story ?

Thanks in advance !!

Thanks & Regards,

Suresh Prabhu