When an Events app page visitor registers for an event, and if everything is configured and working properly between your Soapbox Engage account and Salesforce, Opportunity and Ticket records should be created in your Salesforce org. If you find that a registration exists in Soapbox Engage's Events app but is missing in Salesforce, here's a few things to check.
1) Confirm that your Events app event is associated with a Salesforce Campaign
2) Search for the registrant's name or email address (as listed in the Soapbox Engage Events app) exists in the Lead object in Salesforce, and has the "Registration Match Review Needed" field checked. If so, this means that the registrant matched on two of three elements used for matching to an existing Contact, and will need you to manually convert the Lead to associate it with the right Account and Contact.
Happy event registrations!