The number of protons an atom has depends on what element it is. A hydrogen atom, for example, only has one proton. A nitrogen atom has 7 protons, an atom of antimony has 51 protons and an atom of radium has 88 protons.
Protons also determine the atomic number. Therefore, a hydrogen has an atomic number of 1, while nitrogen has an atomic number of 7.
Protons are found in the nucleus of the atom. They have a positive charge. Normally, there are the same number of electrons in an atom as protons. Since electrons have a negative charge, a normal atom has no charge.