Question

how to find that whether the equation oxidized or reduced ?

Answer 1

Oxidation is the addition of oxygen or removal of hydrogen and reduction is addition of hydrogen or removal of oxygen .The substance in which oxygen is added gets oxidised and the substance in which hydrogen is added gets reduced.
When copper(ii) oxide reacts whit hydrogen, it gives copper and water.

$CuO+\hspace{0.17em}{H}_2\to Cu+\hspace{0.17em}{H}_{2}O$

Here copper oxide is losing oxygen and being reduced and hydrogen is gaining oxygen and is being oxidised.