There are some questions to be answered first,
1. Are you keeping this tree outside?
2. Is this tree deciduous?
3. Did you buy it from somewhere local, or off the internet?
4. What's the soil like? Does the water drain through quickly and does it have coarse material, or does the water stay wet for a long time, with thick soil.
The last thing the tree wants right now is pruning, so I wouldn't recommend pruning it until you know it's safe to do so.
A test you can do is scratch the bark with your fingernail. When you scratch it, is the dark a brown color, or is it green?