The tree that is commonly referred to as a “bonsai” is a dwarf Japanese juniper (Juniper Procumbens Nana) that you can get at any nursery for like $10. try to look at the trunk and pick one that looks easy to prune into the shape you want Take it home prune and shape it then re-pot it. Theses trees will be bigger, older, fuller and healthier than any overpriced mall bonsai. You can just goggle bonsai and find some sites that explain how to prune and stuff, you can buy bonsai pots on eBay. Anyway the term bonsai refers to the art of maintaining the trees, not the kind of tree. you can create a bonsai out of may kinds of trees. Apparently junipers usually die because they are not indoor plants, mine died in my apartment, but it may work better for someone else. I don’t have a green thumb, right now I have a dragon tree, a cactus and a some bamboo, they are all pretty tough and have survived under my rule. For my next bonsai might try a jade or tea tree, apparently subtropical trees live indoors better.