Help my squarespace website with integration to Hubspot

We are an online education company, and we are selling subscription products (class packages) on Squarespace. Customers can create an account with us. We use Hubspot as a CRM tool and are also sending out class reminders/ marketing emails to customers. What we want to achieve is: 1. When a customer subscribes to one of the class packages on Squarespace and checks out, his/her contact information is created or updated in Hubspot, AND the type of package and the date when the purchase is made should also be stored to Hubspot 2. We need the type of package to be stored in Hubspot because: There are two packages that renew on different frequencies; One is 8 classes every 2 months, another is 42 classes every 12 months. Although Squarespace can automatically renew these packages, we still need to track the # of classes a customer has taken so it doesn't exceed the maximum number. For this reason, we need to build a workflow on Hubspot to be triggered by the action of purchase and automatically sends class reminders for each class so when it hits the maximum #, it will send an internal email to us notifying us that this customer has run out of classes. Note: we have a Zapier account if needed.