1) Bring your ear defenders. My DD used to bring hers to the parks and use them when things got to be too much. Then she transitioned to using earbuds and listening to music she likes on her phone. But for our next trip, she's said she will be bringing her ear defenders again.
Besides noise, you don't indicate what other things aggravate your sensory issues. Sunglasses help DD. We also take breaks during the day. You should also read up on the Disability Assistance Service. There is a sticky thread at the top of this forum. There's no need to read the full thread. Just reading the first post will give you the vital information:
https://www.disboards.com/threads/w...genie-post-one-is-an-updated-summary.3849395/
2) I can't help with this as I've never dealt with it.
3) There are a lot of different learning disabilities with different impacts. Without knowing how your learning disabilities impact your day to day life, I'm not able to give advice on how that might impact your trip.