Higher wing loadings normally make a difference during the low speed phases of flight, for example a lightly loaded trainer is very forgiving to slow down and land, perhaps to the extent that it permits bad habits to be learned.

A scale warbird on the other hand is always deemed to be totally unsuitable for beginners. The reason for this is that the high wing loading means a higher stall speed. Warbirds don't like flying slow thus landings take much more judgement and skill than a trainer needs.

Flying slowly, a high wing loading will mean you're aircraft is easy to stall, either by plain flying too slow, or by pulling a tight turn at lowish speeds. Conversely, as said above, if your speed is high enough that you don't stall first, your wings will clap hands [:@]

The Wing loadings is basically an expression to judge how hard the wing must work to fly any given aircraft. Clearly, the warbird wing in the example above must work much harder than the typical trainer. You may also find (but this is not without exception) that higher wing loadings correlate to worse manners, eg there is less warning of an approaching stall etc.