start with i3wm/sway or openbox. openbox is a floating window manager so it should be more familiar and i3wm is a tiling window manager. personally i use kde nowadays but i always preferred tiling window managers when i chose to use one. it all comes down to your choices so first see if you prefer tiling or floating window managers and then go from there

I’d recommend sway and waybar. Waybar offers some cool customizable templates. Currently I also use bemenu as a launcher and dunst/poweralertd for notifications. I make heavy use of stacked or tabbed layout during general use.

sway has pretty decent mouse support, but for optimal productivity try to get used to the keyboard shortcuts. As soon as moving/resizing windows and changing desktops becomes muscle memory it’s a whole different ball game.