Hello - looking for tips from those more experienced

I live in Virginia and have arranged to rent a R1200RT in England at the end of September and take a ferry down to Bilbao for a week of riding around Spain. I expect the temperatures to be in the 80's and 90's. Hotels at night so no camping planned

I am really interested in tips for how to dress and pack an RT ride for a week riding in hot weather, with a good risk of rain. I have all sorts of gear but I need to think the herd out so to speak. Essentials versus nice to have etc I am not expecting to have to dress smart for anyone so I am keeping it down to riding gear plus a shirt for the plane each way.

Also interested in good medical insurance for a trip like this.

Thanks!