What kind of program did you create (e.g., what channel type)? If the channel is default, you will have to create a smart campaign -- create new smart campaign, define the smart list (who receives it) and then define the flow (select the email you want to use) and then schedule. If you used the "email channel" it should automatically appear in a drop down on the control panel under the "email section".
My guess is you created a default program type, which means you will need to create a smart campaign.
Hi Lauren,
No problem. I'm a bit confused by what your issue is. Are you trying to add "who you want the email sent to" which coudd be done in the smart list by slecticing specific filters, or are you trying to access the email that you want to send?
If you already have your smart list selected and you just need to select the email (in the flow) section, there should be a drop down in the send email section.
Have you already created the email in Marketo?
Steve