You can learn from those you carry on your back to cross the shallows.

Literal

Carried child [by-に] taught [then-て] shallows [object-を] cross.

A proverb meaning you can learn even from those younger or less experienced than you. 負うた is the classical past of 負う (to carry on one's back). 教えられて is passive — 'being taught by.' The imagery is of a parent carrying a child who spots a safe path through shallow water.