I just moved from Quickbooks Mac 2019 to Quickbooks Online for our C corporation. The operation was seamless for the most part but there is a lot of little "nooks & crannies"  you need to find and adjust like start of the corporate year, etc... It will take a few hours/days to learn all the menus and adjustments but once it's done I'm liking it more as time goes on..

 

I to have the "access denied" here on some of the instructional videos and files and I have full administrative privileges to our account .. Quickbooks admin needs to fix this...