Surely, before being sent on a solo cross-country trip his instructor(s) should have taught him the in-flight use of VOR and ADF as a back-up to map reading?
Learning VOR and ADF would be a complete waste of time and money.
The GOTO button is your friend!
I have carried at least one GPS when flying since 1991.
In the 43 years I have been flying the 3 greatest advances in GA have been GPS, digital fuel flow and all cylinder engine monitors.