The graph in slide 11 is the radial part of a wave function, we need to square this to get the probability density function. Then it would be a graph starting from 0,04 after which it’d make a hill.
I would describe this to a child as some sort of diffuse spherical shell, with a darker zone at the atomic radius and very bright at infinity. The child would not be standing in total brightness, but there would be some dark in his spot.
An electron does not follow a clear set path, it feels many forces and thus can be in many places. However, it generally stays in the same zone, as it would need extreme energies or luck to travel far distances from the core or to very close distances. On average the electron stays on a shell around the nucleus.