Tree Pruning

This is a tree I got last year from Woodland Gardens in Manchester, Connecticut when it was not more than 3″ tall. My original intention was to make a tiny bonsai but it grew rapidly and is now a small, woody-stemmed tree. The tag on it said it was Myrrh, but it’s looking somewhat like myrtle. I honestly have no idea what it is, but it’s being trained wtih copper wire into what I hope will be a living waterfall.