There is very little room for any furniture in that space and still be able to navigate as a walkway. A bistro set would fit but not anything any larger. An indoor-outdoor carpet and a couple of planted containers and the space is full and good to go!

To me this looks more like a walk through space rather than a hang out space. However, if you want to use it as a living space, do you need to keep the walkway clear both directions for regular use? For example, if you mostly go from the door to the stairs, then you could probably put some furniture between the door and the window well. But if you need to go both directions regularly, I would avoid putting furniture that has to be navigated around.