Start with a tree that is both healthy and appealing to you. These two points matter more than anything else in the beginning. For beginners, the safest choice is a deciduous tree with strong, vigorous roots. In Japan, these are often grouped as zoki (broadleaf species, including flowering and fruiting types), and they tend to be more forgiving.
Among them, Chinese Elm, Firethorn (Pyracantha), and Trident Maple are especially reliable. They grow actively, recover well, and tolerate small mistakes, making them excellent first trees. Depending on your region, Ficus is also commonly recommended for similar reasons. Start by choosing a tree from this group—something healthy, and something you genuinely like. That alone is a strong beginning.
When purchasing a tree, it is worth asking when it was last repotted and when it should be repotted next. This simple step helps you avoid unnecessary stress on the tree. Timing also matters. For beginners, it is best to acquire a tree after bud break, during the warmer growing season. In colder months, especially with deciduous trees, it can be difficult to judge health when there are no leaves. If you are interested in flowers or fruit, choose a tree when it is actually in bloom or bearing fruit, as quality can vary significantly between individual trees.
If you are looking for something more refined from the start, it helps to learn the basics of bonsai styles and how to recognize good material. With that knowledge, you can choose either a tree that is already enjoyable to display or a pre-bonsai with strong future potential. At first, however, it is perfectly fine to simply choose something you like. As you gain experience, you can begin shaping trees yourself.