If you are inland, the only interview you typically have to attend is a final, landing interview. You won't be able to schedule it until your application is complete, and even then, it's up to the local office to do the scheduling.
You can't schedule it yourself because your sponsor is required to attend to confirm they still wish to sponsor you. You can request the landing interview be scheduled when your husband is available, but you won't be able to do that until your application is complete and you have an initial invitation.
Calling them right now would be rather pointless
I would also be concerned about calling them right now and saying that your husband is gone for six months - while there is some leeway in the procedures around Canadian service members, there is a requirement that you live with your sponsor during a sponsorship application. Him being away for six months may be a challenge.
If I were to give you advice, it would be to wait until you have an interview request and then request it be postponed as he's in the military.