>>1608736What's his level? Typically walls like this are between 25 and 60 degrees overhanging, most people settle around 40
Make sure to consult him a bit on what he likes and want since he'll be the main user
>>How to course set? I would just place all kind of holds everywhere and set problems once it's up. Also add some extra foot jibs here and there + a lot of them on the bottom. (easier with a few other climbers wanting to make some problems for you) Then you reset it maybe once a year when you get bored with it. (maybe for the first time, be prepared to reset after a few months from the gained experience)
Some boards (see moonboard for instance) are set like a grid so you can use A5,E8,I12 to refer to holds.
Some old school ones straight up name their holds, see pic related
A common way is also to take a picture of the wall and circle holds to use for a given problem, there are also some apps designated to do this. (stokd I think?)
Additionnal info :
classic metolius pdf guide :
https://www.metoliusclimbing.com/pdf/How-to-Build-a-Home-Climbing-Wall.pdfFor holds you can ask companies if they has some defect/seconds to sell, eventually some gyms also sometimes get rid of some old ones.
There is a video on "mani the monkey" youtube channel where they build a spray wall at their gym, you might gather some thoughts from there too.
https://www.youtube.com/watch?v=spTKbJPPCOIThere is a video of Dave MacLeod about making wooden holds which is worth the watch too.
https://www.youtube.com/watch?v=s3kQZPtgzTA 
