You need visitor visas and written authorization to travel to show your visit is essential and necessary. Do you have sole custody? If so you will need to show that. Because you are not married you may have a difficult time getting approval.
You hotel quarantine at your Port of Entry so Toronto. You book using the government provided phone line and only book with one of the approved hotels. When cleared, you can continue to Calgary and finish quarantine there.
Did he not include you on his application? Do you have a visitor visa? If not apply. Are you bringing your child and does child have a passport and visa? Was the child included in your husband's application?