No, any electron amplitude with absolute value (squared) equal to one corresponds to a probability density of 1 to find an electron. You can have a positron wav

No, any electron amplitude with absolute value (squared) equal to one corresponds to a probability density of 1 to find an electron. You can have a positron wavefunction if you have a positron, but take care that you don’t have both, or they will (even if with a vanishingly small probability) meet and, by participating in a process with energy comparable to mass, boot you right out of nonrelativistic quantum mechanics into quantum field theory. I hate to tell people to learn A before they can try B, but here I really, really don’t know of a way to start thinking about QFT with its positrons and annihilation and so on without getting hopelessly confused unless you’re already comfortable with normal wavefunctions-and-Schrödinger’s-equation QM. You’ll still be confused even if you are comfortable with it, mind you, it’s just that then you’ll at least have a ghost of a chance of getting your confusion down to manageable levels.