Users/licenses vary based on the version of QuickBooks you have. At a minimum, with QuickBooks Desktop Pro, you can have 3 users/licenses. You should be able to download on 2 computers and work between them. As you indicated, it will be really important to make sure you are backing up and restoring each time so that your company file is accurate on each computer.
Another option for you is hosting. Hosting would allow you and your team (up to the maximum number of users) to work from anywhere and access your company file in the cloud. I am including some information here.
Let me know if you have any questions or need any additional information on hosting. I am just a comment away!