For smaller groups (eg, Advanced/Challenge classes or tape groups), Schedules space generally makes more sense than CAC space. Schedules now has an online interface for reserving rooms – you can even pick a specific room that is probably available, but you should still give them guidance on what properties you want, because sometimes your choice will turn out to be unexpectedly unavailable.
The "Room Reservations" folder of the officers' Google Drive has a doc called "Squares Reservations naomi" with a tab called "Room Preferences" that has some additional comments. (Not linked here since this page is public, and the doc is shared by link.)
Obviously, update appropriately, but these might be a good starting point for a tape group.
Event name: C1 workshop
Sponsoring organization: Tech Squares
Purpose: Practice C1
Are you...: student (alums should choose student, not faculty/staff)
Event classification: Other
Expected attendance: 10
Non-MIT: 20%
Requester information: yourself + Schurr, Naomi
See above for choices
Note to schedules:
If this room isn't available, we'd like a flat, tiled room of >800sq ft with movable furniture.