I'm a beginner myself even though I've been at it for a quite a few years by now. I've found that the best way to learn to care for them is to start by practicing on young trees that appear in my back yard. For instance, mulberries sown by birds are always popping up and after a season or two left in the ground I transplant them to pots and use them to practice branch and root trimming on and try out a variety of soil mixes. Since I have a constant supply of new ones coming up it is no great loss if I lose a few in the process. I highly recommend you use this method to develop some basic skills and you might end up with some trees you really like.