Hello TaniaS,
Depending on what kind/type of membership (one time sign up or subscription) and how much data (name, address, phone, email, etc.) you need to collect would be helpful for other members to provide some suggestions. It's not always easy collecting the data you need using Square's tools as input text fields are limited. You could create an item with some additional text input fields and generate a Buy Now Button or QR Code or simply a URL Link. Note, there is higher processing fee for Payment Links. If going with Subscriptions - there is an additional monthly cost to consider.
Thinking outside the box, if this is just a one time sign registration and you need a lot of data, you could use an app like JotForms. JotForms has lots of pre-built Templates for sport club registrations/memberships you can customize or even build from scratch. JotForms also can be connected to Square for processing the payment. Once your form is created it is stored on JotForms servers and you are provided with a link that can be shared. I've tinkered with this app creating some things I could not do with Square - there's a learning curve as with any app but, it does work. I'm sure some of the other Community Members have some thoughts too as there's always more than one way to do something.
