Try doing a system update and if it is available, should give you the option to upgrade free. Windows 11 is right around the corner but isn’t “officially” available yet.
The answer to that looks to be no. We tried it last month and the free update from 7 to 10 is no longer working.
BUT! If you had installed W10 then rolled back we did find that we could install 10 and avoid buying a license because of how Microsoft implemented licensing.
All that aside, if you were to try to upgrade from 7 to 10 using any of the web pages how to do that, the recurring advice is to backup what you can’t lose.