So, hab mal einiges grammatikalisch und stilistisch verbessert, die gröbsten Verbesserungen sind Fett und Kursiv markiert, damit du vergleichen kannst.
The time with your family was wonderful. I had a lot of fun during this time, which I will never forget. My favorite activity was surfing at the beach, which was really nice. The trip to London and The London Eye was amazing too, but I hated the classes there, since they were boring. The food is really yummy in England, because I like fish, which is very popular there. Well, I hope you and your family stay healthy. Reply to me soon.