If last year's setup didn't present problems, start by measuring present caster, camber, toe, tread width at both ends and front and rear stagger and throw it on the scales and get those numbers. That will give you an idea of where to go and which adjustment would be best to head in what direction to achieve the desired change(s).
Other than that, someone with more knowledge of that particular make and model will undoubtedly post a baseline setup you can use for a starting place. Just keep in mind that any setup will have to be tweaked to suit driver preferences - and that's over and above tweaks for different track conditions. Since he has a year under his belt, in spite of his young age, his input will definitely be useful, even if it is only whether the setup felt better or worse than the last time he was on the track.