At this stage, you shouldn’t be using a shampoo as the length is still fairly short. I’d recommend using a natural bar of soap that doesn’t have irritant chemicals in them (like sodium laurth sulfate). There are a lot of soap options out there, and one I’ve personally used and enjoyed is Rocky Top Soap.
Once you get through the itchy phase, you’ll get to the point where your beard will look untidy. To neaten up your look, I recommend trimming the neckline, upper cheeks, and mustache lip. If you are going for the yeard, or natural beard, you should leave your beard untouched.