You cannot automate setting a followup after logging a contact. However, after you log the contact, you can add a followup from the followup widget at the top right of a person's profile. If coffee date is already a contact type, you can select it from the followup drop-down menu, then select the due date of the followup from the calendar pop-up. If coffee date isn't already a contact type, you can add it at Settings > Defaults > Contact types. 

If a person has an open followup, when you are logging a contact you can check a box to "mark as followed up for [contact type]."