Howdy Kevin,
It’s nice to meet you.
That’s certainly not a dumb question. Our plugin, including Community Events, uses WordPress’ users. If a user is registered on your WordPress website, they are already registered for Community Events once you activate that plugin.
Is your ecommerce solution one of WordPress ones, such as WooCommerce? If so, then user accounts will be shared no problem. If it is not based on WordPress then users will probably not be shared with The Events Calendar. However, if you are planning to use Community you can set it up to allow anonymous submission, so that users do not need to register.
Does that answer your question?
Cheers!
– Brook