Normally GiveNow uses the cause name as a cause campaign name in Salesforce. You can override the default campaign name. GiveNow has a special field against the cause called Salesforce Campaign Name, which appears after the Salesforce integration has been created.
To modify the Salesforce Campaign Name for the cause, from OrgHQ, click 'edit' next to the relevant cause and complete the 'Salesforce Campaign Name' field at the bottom of the first page of the edit cause form.