Airline Carry On Rules

I’m drifting upon Northwest Airlines and we was wondering if there is a singular volume of glass we can bring. we know it has to be 3 ounces or reduction in a quart-sized ziplock bag, though how most of those 3 unit bagged liquids am we authorised to bring? Am we usually authorised to have a single square of container to lift on? For ladies, does a purse equate as carry-on container if I’m usually authorised to move a single suitcase? What have been the boundary for carry-on baggage? Help!!!
Does a cloak validate as a carry-on object or can we be wearing a coat/jacket, carrying a purse, and lugging a square of luggage all at the same time?