A neutron has almost the same mass as the proton, but no charge. The usual kind of helium contains two protons and two neutrons in its nucleus. Some elements exist in more than one form, which differ only in the number of neutrons in the nucleus. For example, carbon has three forms, which are called isotopes , of which carbon-12 is by far the most common. The usual kind of hydrogen does not contain any neutrons in its nucleus.
Normal hydrogen consists simply of one proton and one electron.
It is much more important that you understand electrons and protons. In between orbits are not allowed. The reasons for this depend on quantum theory, which is one of the major theories of physics. Different electron orbits require different energies . To move an electron from a small orbit, near the nucleus, to a larger orbit, farther away from the nucleus, requires you to give the atom energy.