I had an absolute blast at the amusement park from opening to closing.
ご質問ありがとうございます。
このシチュエーションで、[遊園地](https://eikaiwa.dmm.com/uknow/questions/34289/)で、開園から閉園まで、乗り物に乗りまくって、楽しんだと言いたいなら、英語で「I had an absolute blast at the amusement park from opening to closing.」と言えます。
ご参考になれば幸いです。
From when the park opened and to when the park closed, I had so much fun.
"開園から閉園までめいいっぱい楽しんだ"
- From when the park opened and to when the park closed, I had so much fun.
- I thoroughly enjoyed myself from the opening to the closing of the park.
遊園地で、開園から閉園まで、乗り物に乗りまくって、楽しんだ
- I had so much fun riding all of the rides from the amusement park's opening to closing time.
アメリカ合衆国 
