Data linking between Calendar OR Task and Product?

Data linking between Calendar OR Task and Product?

We are looking to use ZOHO for scheduling our coaching classes. Currently, we enroll people in classes through Products, and we would like to use either Tasks or Calendar as our master schedule, while keeping enrollment through products. 
- Is it possible to have a product link to either an event in Calendar or a task in Projects?
- If we upgrade to be able to create custom fields, can we add exact times in Tasks?
- Can we add custom fields to calendar events?
- Are there any other calendar features that are unlocked if we move to ZOHO ONE?
- Does anyone have other suggestions to how we could utilize ZOHO in this manner?

Thank you!
- Erin