You need to take a CPI course and test. Once you have your CPI you can register with the SAS of your choice and look at what spectrum is available in your area and start using gear in GAA spectrum.
The CBRS sub section may be a better spot to ask this question, but I don’t know of any video provided by Cambium explaining how to get started. They do offer this guide that has details:
Like Jacob mention, getting your CPI is a good first step. It is required to operate in CBRS. Also if you don’t have cnMaestro setup yet either Cloud or On-Prem, then you should work to get that setup first before purchasing equipment. Its required due to it handling the communication to your SAS. Those are the major components needed to get started.