Okay. I’m not sure how the dimensioning tool is in KiCAD but in DipTrace it’s pretty robust.
It’s pretty straight forward. To get the general layout, you’ll want to get the dimensions and spacing of the pots.
On a standard 3 knob the top pots are spaced at 33mm and the center knob is 25.4mm lower. The holes in the PCB are 16mm from the PCB pads for board mounted pots.
Once you get your mechanicals set, pots, switches, I/O, etc., it’s just down to getting a board outline that works and doing the design.
You can make array grids as footprints to match the pot hole spacing, for starters. Treat them as templates and delete after you get the pot footprints correctly aligned on the hole centers.
I use EasyEDA and for mine I just put the pot footprint at the coordinates given for the predrilled pedalpcb enclosure I want to use from Tayda or whatever my custom drill set up is. In my case the pads are offset the appropriate distance from the footprints center point, but if your footprint isn't then you have to do the math, I'm not sure if KiCad has XY coordinates like this, but I've found this really convenient.
You can also use the same process you use to add logos to PCB designs (plenty of tutorials on YT) to add your drill template to the design. That's what I've done in the past. I just eyeballed the pot placement from there and deleted the drill template when I was done.