Hi Marc,
Yes, I remember your situation.
Good job on starting a conversation with her at school.
Now, she did tell you that she doesn’t like funfairs. But, you went ahead and suggested going to a funfair next week.
It isn’t a surprise that she didn’t take you up on your offer.
Yes, you should go on the offensive, but try not to go overboard with telling her about how much you like her.
Instead, focus more so on asking her out the right way.
If you are unsure of what to do, keep it simple. Ask her to coffee, lunch, or dinner and a movie.
Until you ask her out on a proper date, you will not really be able to determine whether she is open to going out with you in a romantic capacity or not.