How and where can I customize the language I can present to my visitors? I also need to configure the email notifications so I can customize them in Spanish. Can this be done?

To modify the preferred language on the booking page, navigate to Settings (icon) > Workspaces (Select the workspaces) > Policies & Preferences > Language (change accordingly). Regarding the email notification customisation, you can do that under Service -> Service Notification ->For Customer/For Staff > Booked > Customize. Kindly refer to the document.