Purchase includes an 1 hour of consultancy that will get you set up and running in your Bubble App.
Setting up taking payments and card storage requires;

A Square Application setup - (application id, location from Square)
The Square Plugin Element (drag this plugin onto your Bubble page)
Bubble input fields for cardholder name and address (used for card authentication)
Bubble Backend Workflows one for storing cards & and one for taking payments) within your Bubble Application to receive the card token and details from the Plugin and send them to Square.  (you can copy the setup of those from this app)

Then within your Bubble Backend workflows, you can capture and record payment and card on file token details, and request payments.

You can view how the Bubble sample app is put together here: https://bubble.io/page?name=index&id=square-payments-plugin&test_plugin=1654618927193x637538826809245700_current&tab=tabs-1

There is a Youtube video channel with many explainer videos here https://www.youtube.com/playlist?list=PLpZXz2W3mS45coM4yG7OQoPOO_6btVS_Q

If you've purchased this plugin I'd really like to make sure that I get this working properly for you. The plugin price includes reasonable support needed to get you up and running.

Contact me in the forum @lindsay_knowcode for help