There’s no way to add docked toolbars but you could create something similar to the Default Tray (what I presume you are calling a “side bar”.) The windows can be stacked together and moved over to the side to sort of look like the tray. When I used SketchUp on both PC and Mac which was before the Default Tray was introduced, I would just make the model window just narrow enough so I could keep the utility windows over to the side. This is a screenshot from my setup of SU2015 on the PC. It was similar on the mac except for the toolbars.
The other solution would be to go back to PC.