Within each event type, you'll have the ability to edit/change the order of activities that you have set up into an order you'd prefer. This order is how the activities will display on your website when participants sign up and attend.
The steps within this guide are the same regardless of what event type you have created.
Firstly, you'll need to head to the Events Module within the Admin Area and select the event you'd like to edit - the event will need to have 2+ activities set up for you to be able to edit the order they appear in.
You'll then need to scroll to the bottom of the page, where you'll see your activities listed:
By clicking anywhere on your list of activities, you'll be able to drag them and re-order them.
Once you have finished re-ordering your activities, remember to click on the blue 'Save Event' button at the bottom of the page to save your changes.