Help with a tree please

[raindropsies]

I planted (or should I say got Paul to plant) a tree

This was about 4 years ago, and this year it's started to produce fruit.

We are not sure what this fruit is but think it's possibly plums

Now there are branches really high and to the sides, when would be best to prune it (if you do prune trees) and how much should be pruned?

Many thanks in advance

[CornishDave]

Put 'pruning plum trees' or 'pruning fruit trees' in Google search engine, and all your questions will be answered. Good Luck. Eileen.