Do you have a license for SketchUp Pro 2015? If so, you should check on the SketchUp site regarding upgrading your license. It wouldn’t cost anywhere close to the 588 you see for a new license.
And if you are using it for personal use you could just use SketchUp Make.
I experienced your problem when I tried to run 2015 Pro on my Mac after installing Sierra. Graded-up to 2017 Pro, about $200, and have had few problems since.
The simplest way for you is to down-date your OS to whichever Mac OS is suggested for 2015. It will be a free ( or $25) replacement on the App store, and you’ll be able to draw again using SketchUp instead of retreating to Punch.