With kart on the stand – Make a chalk mark line on each tire, doesn’t matter where. Rotate tire till chalk mark is at the front of the kart, measure from mark on Left tire to mark on Right tire.
Now rotate chalk mark to the face rear (as far as you can go with snaking a tape measure between the steering and brake components). Measure from mark on Left tire to mark on Right tire.
If measurement across the front was larger then measurement across the rear you have toe out.
If measurement across the rear was larger then measurement across the front you have toe in.
Place kart on flat surface. Place right angle perpendicular to tire touching the furthest sticking out point. Assuming there is negative camber, measure the gap from tire to right angle at the top. If you have positive camber on the tire there will be a gap on the bottom of the tire (not common in sprint karting).