Backpack, capes and fighting

Hello, I am new to DND, I have been playing about 9 sessions and I am enjoying the game. Our DM is a bit flexible since most of us are new. I am playing with a halfling rogue and I am questioning the logistics of carrying stuff and outfit (also want to make a drawing and 3d model of my character ). So my question is how do you address the issue of using a backpack and a cape at the same time? Closest thing I saw was lotr Sam with his cape and backpack, but it doesn't seems very handy for a rogue fighting style. Do you normally say you wear the cape above the backpack?

Another consideration for any character, do you fight with the backpack or you just throw/leave it on the floor?