I messed up the name of my event. What can I do to edit it?
Alternatively, you can use Lexicon under your "Data Management" section to re-name Events using the "Display Name" field. This also gives you added features in that you can also add event and property descriptions as well, which will show up in the core reports when building queries and reports.
You cannot rename old events. The best thing you can do is create a "Custom Event" to include all variations of your event: https://help.mixpanel.com/hc/en-us/articles/115004519426-Change-Event-Name-Or-Property-Name