Welcome to Community, @beccaranieri!
I understand you're confusion as to why there's no "Add Client" in your QuickBooks Online Account. Let me share my insights.
The Add Client feature is specifically designed for QuickBooks Online Accountant (QBOA) and isn't available in regular QuickBooks Online (QBO). However, if you're using QBO, you have the option to invite your accountant to collaborate on your account.
You can visit this link for future reference if you want to add a user to your QuickBooks Online Account:
If you have further concerns aside from this, please don't hesitate to reach out. We're here to help you. Have a great day ahead!