Defender Office 365 Plan 2. HELP!!!!

I need anti- phishing security for my small business. I have a Google Workspace to have my own domain, which was set up that way. Many of my employees have opened phishing emails. Because I only have about 15 workers, the most cost-effective software is the Microsoft Office 365 plan 2. We didn't pick this one, but the sales rep stated this would work for our needs.

Now linking our Google Workspace emails is becoming a nightmare. My employees do not have IT capabilities to set these up. Microsoft was great in their sales division, while purchasing the software was great. Now it seems I cannot get help. They rarely answer the phone, and when they do, they transfer me to someone who NEVER answers.

I am not sure if there are video tutorials for all this. The cost is the only thing that is making me try to stay on this platform. But I might end up paying more and going elsewhere. Microsoft is not what it used to be.

I did find tutorials on settings to stay protected in my admin part but the I don't see any information on anything else. I did tell the sales rep that my team does not have Office 365 and that I only pay for it for 5 managers. But how do I add all the rest that do not have Office? This is turning out to be more work than help.