Window managers can be a little intimidating at first, be advised.
Openbox edition, although almost as frugal as Bspwm or the others WM, it is a little bit more forgiving being a "floating window" paradigm like usual desktop environments, so you could give it a try also. Awesome WM, also has optional floating windows and titlebars, buttons and all that. It is heavier, but less so than XFCE still.
And anyway, coming from windows, you should give a try to the Live sessions of XFCE, Mate, or even better, LXDE/LXQT. Frankly, I would be deeply surprised if your machine can't run those particular two DE's. They are almost as light as WMs.