Hi - I'm assuming you are trying to make a campaign available via the "Add to Marketo Campaign" feature in Sales Insight?
No, not all triggered campaigns become available in Sales Insight. You need to choose which ones will be available.
You do need to build a campaign in Marketo - if it is a triggered campaign, the trigger should be "Campaign is Requested", and the source should be "Sales Insight". Once you have set this trigger, and approved the campaign, it will become available in Sales Insight.