If you click the magnifying glass in the top-right corner and type "term", can you run the Terminal from there?
Hyper might also work.
Are you opening Anaconda Navigator OK, and seeing the Jupyter icon there? Does it display any messages or output when you try to run it?
If the system is a fairly locked down system from school or work or something like that, and disables the Terminal for that reason, the owner may also not want you to run Python or Jupyter. From inside Python, you can run the same system commands that you would run in a Terminal window, as described here:
You might try talking with the computer's owner or administrator, explaining to them that you want to learn Python and will use the system responsibly, and asking nicely for access.
Disabling shell access was a little more common a few years ago, but these days most administrators are becoming somewhat more permissive. In fact, there are now even some sites that will let you use a web browser to access Python on Jupyter on *their* machines, as long as you don't start mining Bitcoin or otherwise using up too many resources.