I've seen several people online (specifically photographers) asking about the best way to do event sign-ups on their Squarespace website. Squarespace does have an Event Block, but it doesn't currently have an option for sign-ups. Lucky for you, I know an easy workaround for that.
Event registrations in Squarespace:
First, you're going to create a Product. Name this whatever you want your audience to see it as - "Holiday Mini Sessions" for example. You'll want to select Service as the product type when setting it up.
From there, you'll be able to add details and specifics of the event. Upload a thumbnail, give the details of the time and place in the description, etc.
But, we really want to focus on the Variants. This is what will give your clients the different options for your event. You could make day of the week and time two separate variants, but choosing "2:00" and "Sunday" would take away "2:00" and "Monday" as an option.
Here's a look at what the sign-up will look like to your audience.
They will pay for their time slot, and get a confirmation email. You, too, can view a spreadsheet of all your event sign-ups with all of their contact information.
Pssst: Be sure to check out my ebook! A step-by-step guide to Squarespace SEO!