Backpack or suitcase is a matter of personal preference. You can definitely follow a backpack travel style with traditional luggage. However, for the budget traveler a backpack makes a lot of sense. You’ll be taking subways and buses and probably doing lots of walking to get to your lodgings, staying in hostels without elevators where reception is 1 floor above street level and your room 2 floors above that. Wheeled luggage doesn’t work well on cobblestone streets, with curbs, or going up stairs from the train or subway station. Load up your traditional luggage, carry it around the block twice and then immediately up 2 flights of stairs. Then decide whether you want to invest in a backpack.

With your short trip, I’d look at getting an inexpensive backpack that’s small enough to use for your carry-on.

Well since I do need a backpack, thanks for the advice oldlady, if anyone has a backpack that is outdated or no longer used please message or post on here, and thanks everyone for the invaluable counselorship that you have provided me.