Once you've set up your plans, you'll need to get people into classes or events. You can control many of the attributes about the class or event. Everything from setting attendance caps, to assigning an assistant coach, to when a member can register for a spot. Below are the basics in setting up your gym's calendar.

First, if you are using Gmail, you will want to set up the Google connecting. This will sync any classes you are scheduled to coach, as well as any appointments, right to your Google calendar.
Detailed instructions here

Generally, any class that repeats would fall under this category. This could be CrossFit, yoga, endurance, Strongman, etc. Classes are generally setup to recur indefinitely, until they are cancelled. Thus there is no need for an end date.
Detailed instructions here

Events are one-time calendar items which may or may not span multiple days. They can be set as a free, discounted, or paid event. Competitions, fundraisers, and special events would fall under this category
Detail instructions here
*Note: You may want to give your members a discount for the event, over non-members. Create Event Discount. 

Open gym allows for members to check-in to your gym, without having to check into a specific class.
Detailed instruction here