You open the product and get an error box stating the license checkout timeout occurred and have to close the product
This problem is related to the Autodesk Desktop Licensing system
This is a fairly common issue with the 2020 software, and the fix is generally pretty painless. See the link below for information on how to correct that issue:
Basically, first step is to install the licensing service update:
Once that specific service is updated, it generally fixes the issue you are experiencing. If you are unsure that it's installed, go here: C:\Program Files (x86)\Common Files\Autodesk Shared\AdskLicensing\ and confirm you see the 18.104.22.1681 folder is there.
If that doesn't correct the issue then do the following:
Click on your start button and type in Services (then click on the Services with gears next to it) this should open the Windows Services on your PC. Go down the list until you see Autodesk Desktop Licensing Service and see if it shows as Running. If it's not running, right mouse click on Autodesk Desktop Licensing Service and select Start from that list. If you can start it successfully, open AutoCAD. If you get an error starting (generally you will get either 1053 or 1067 error if it will not start).
For a 1053 error (do options 2 & 3):
If the Autodesk Desktop Licensing Service is running then, check your Autodesk Desktop app and run any AutoCAD updates first, then run the Autodesk Single Sign On Component 2020.1 (22.214.171.1240) 64-Bit - Update if you have not already done so. Reboot and then retest to see if the issue is resolved.