Family Trip ,1st time to USA

Hello everyone,
My mother was diagnosed with a progressive neurodegenerative disease so we decided to do once in a lifetime family trip to the USA
I will graduate in june and start working in WV,family will be visiting from the middle east
my graduation is on 6/6 in WV
we are planing close to 21 days including my graduation and the travel time before that
Family wants Florida,Chicago,NYC,Washington,California/Vegas
I wanna ask you guys about your recommendations,how many days are sufficient for each and what will be the best route to travel,and shall we do hotels or airbnb?
and lastly any specific activities in those areas or do u even recommend other areas/states to visit?
Appreciate your help!