Hey kailea, we're going to need better and closer photographs of the leaves to be able to identify. Also, if you think insects are annoying inside the house you should remove them. I don't think they will harm your tree, but I'm not too sure. Toadstools appear mostly around rotting wood, so if I were you I'd check the tree on rot.
By the way, bonsai do not really like it when you put a stone against it. In the pot is okay, but it shouldn't lean against the tree