Sorry, for asking you the same thing again, but I really don't know if I have to leave these two sentences as they are.
1. I have already been at school today.
2. I have already been to school today.
(Is there a difference between them?)
3.I haven't been to the cinema yet to day.
4. I have gotten this scooter for three months (this is a mistake?)
1 and 2 are correct. In that context, in and at mean the same thing.
3 is fine, except for the spelling of today.
4 is incorrect. You could write any of the following:
I got this scooter three months ago.
I have had this scooter for three months.
I bought this scooter three months ago.