Also my favorite destination in Asia so far, I went there in 2014 and 2016.
Bagan is a must, so many stunning temples. If you are in good shape and depending on the temperature, I would recommend just biking around the temples.
Hotel around Inle Lake: ViewPoint Lodge & Fine Cuisines
Hotel in Bagan (stay in the 'Old Bagan'): Bagan Thande Hotel
Hotel in Yangon: Sule Shangri-La (large corporate hotel but well-located), The Strand (most iconic hotel in Yangon)
Never been to Mandalay as I heard mixed reviews.
Take mosquito repellent, and sunscreen.
Enjoy Dustin Carter