Could you please check and correct my text

Could you please correct my following homework? I would really apreciate your help.

I will never forget my holiday in 2010. My cousin Kate, who was living in Chicago, invited me to come and join her trip around USA.

I had never travelled by plane before, so it wasn’t easy for me to fly alone. Even if I almost missed my connection flight in Milano, because the departure from Vienna had been delayed, I finally came to Chicago in time. I was so tired that I was sleeping whole afternoon. In the evening I went with Kate to a local party. Following day we met friend Amy, who took us for a boat trip and a tour of the city centre. We also went up to the top of the Sears Towers skyscraper.

Next four days we spent with Kate’s parents in Indianapolis. They showed me the town and uncle’s bank. On Sunday morning we went by their old Cadillac to church. They use this car only for similar remarkable events. Uncle Jim showed me his two Harley motorcycles then. He is a big fan of Harley’s. As a bank co-owner he has a lot of expensive toys and gadgets. The rest of the day we spent at their boat at a near lake. I most enjoyed Jet Ski riding and evening’s picnic. We also celebrated the Independence Day - 4th of July. The evening’s fireworks were really amazing.
After spending the first week with our relatives, we went on the road. For the next three weeks we were travelling around the U.S. We went through St. Louis to Colorado and further to the West. We visited a lot of National Parks such as Grand Canyon, Bryce Canyon, Zion, Sequoia N.P., Yellowstone, Grand Teton etc. We gambled in Las Vegas, splashed ourselves in salty waters of the Pacific ocean, enjoyed fun and entertainment in San Diego’s Sea World and Hollywood Studios in Los Angeles, walked through the Golden Gate bridge and streets of San Francisco etc. I spent really wonderful holidays there.

TOEFL listening lectures: How did Queen Elizabeth acknowledge the English victory?

This is well written and it sounds as if you had a fantastic time! I’ve suggested ‘corrections’ in capital letters and provided some explanations within brackets. (Sorry, but that’s the quickest way of making changes in the available editing software).
Please ask if I’ve made any changes you don’t understand.

[color=darkblue]I will never forget my holiday in 2010. My cousin Kate, who was living in Chicago, invited me to come and join her trip around THE USA.

I had never travelled by plane before, so it wasn’t easy for me to fly alone. Even THOUGH I almost missed my connectING flight in Milano because the departure from Vienna had been delayed I finally GOT to Chicago in time. I was so tired that I SLEPT THE whole afternoon. In the evening I went with Kate to a local party. THE following day we met KATE’S friend Amy, who took us for a boat trip and a tour of the city centre. We also went up to the top of the Sears Towers skyscraper.

[color=darkblue]THE next four days weRE spent with Kate’s parents in Indianapolis. They showed me the town and MY uncle’s bank. On Sunday morning we went TO CHURCH IN their old Cadillac. They use this car only for similar IMPORTANT (I’M NOT SURE THAT GOING TO CHURCH CAN BE CONSIDERED ‘REMARKABLE’.) events. Uncle Jim showed me his two Harley motorcycles then. He is a big fan of HARLEYS (NO APOSTROPHE BECAUSE THIS IS A PLURAL, NOT A POSSESSIVE CASE). As a bank co-owner he has a lot of expensive toys and gadgets. The rest of the day we spent at their boat at a nearBY lake. I most enjoyed Jet Ski riding and THE evening’s picnic. We also celebrated the Independence Day - 4th of July. The evening’s fireworks were really amazing.
After spending the first week with our relatives, we went on the road. For the next three weeks we TRAVELLED around the U.S. We went through St. Louis to Colorado and further to the West. We visited a lot of National Parks, such as THE Grand Canyon, Bryce Canyon, Zion, Sequoia N.P., Yellowstone AND Grand Teton (YOU DON’T NEED TO USE ‘SUCH AS’ WITH ‘ETC.’) We gambled in Las Vegas, splashed ourselves in THE salty waters of the Pacific Ocean, enjoyed fun and entertainment in San Diego’s Sea World and Hollywood Studios in Los Angeles, walked ALONG the Golden Gate Bridge and THROUGH THE streets of San Francisco, etc. I spent A really wonderful HOLIDAY there.

Thank you very much for the corrections and explanations.