Assign different user role on purchase of a product

This would require writing some custom code, but that’s not something we can really help write for you. If you want to try it, you can start with this link perhaps:

https://wpglorify.com/change-user-role-after-purchasing-product/

I can also recommend the WooCommerce Developer Resources Portal for resources on developing for WooCommerce.

You can also visit the WooCommerce Facebook group or the #developers channel of the WooCommerce Community Slack. We’re lucky to have a great community of open-source developers for WooCommerce, and many of our developers hang out there, as well.

thank you