Hey Clara,
Wix Events is just a facet of your website at Wix, whereas Eventbrite is a platform strictly dedicated to events.
In terms of pricing, I can’t speak to Eventbrite’s model, but I can share that Wix Events is totally free to install on your site. The only point at which you need a premium plan is if you are selling tickets.
You can learn more about that here https://support.wix.com/en/article/accessing-payment-setup-for-wix-events-tickets
Hope that helps 