Firstly, welcome to GADC!
If you have a moment, post a few words about yourself on #introductions. 
The following post may be of interest … although, like the UK, things are constantly changing.
The following sites give details by country - so check the USA bit.
The first also provides details by state … but that may be more relevant to US resident than visitors.
https://droneregulations.info/
Others that have visited may give their take on things.