Hey Laura,
Thanks for reaching out with your questions. Let me help you with them.
1. To display events having the free version of The Events Calendar is sufficient. Events Calendar Pro is an addition to this, which will give you extra functionality, like recurring events, more calendar views, advanced widgets and so on.
More details here:
The Calendar is Loading Slowly
2. To allow visitors to purchase tickets to the events / courses you will need Event Tickets (free), Event Tickets Plus extension and an eCommerce solution. Our plugins currently support WooCommerce, Easy Digital Downloads, Shopp and WP eCommerce.
For the eCommerce part, all of the core plugins there are free. And of course they also have premium extensions for which you need to pay, but those are not required, only if you need their functionality.
So to sum it up, this is what you strictly need:
- The Events Calendar (free)
- Event Tickets (free)
- Event Tickets Plus (from $89)
- an eCommerce solution (core is free)
I hope this helps. Let me know if you have any more questions, I’d be happy to help.
Cheers,
Andras