Hi Mariah,
There are a couple of pieces to this.
You can create an entry in the Program Schedule View and then create a Smart Campaign or a Email Blast Program by changing the "Type" of the basic entry. This will create a tentative entry connected to the Smart Campaign or Email Blast Program.
In the case of an email blast program a tentative entry will also get automatically created if you populate the date in them but have not yet approved the program.
Let me know if I can help with more info.
Aj