By default Mobilize organize your feed in a way that is targeted to the user viewing it, including sorting by distance if the user has entered a location or by upcoming time if not. You can also pin events to the top of your feed using the "Action" menu next to the event from your Dashboard event list and selecting "Pin to Feed." Your pinned events will have a star next to them on the events list.
Events that you pin will automatically rise to the top of your Feed and will show a "Highest Priority" indicator:
Pro Tip: You can adjust the order of High Priority events by un-pinning and re-pinning the event in your Dashboard. The events that have been most recently marked as pinned will appear first in the Events Feed.