How to expand jaw and muscle growth

[Goodluck]

I am alr pretty sure my palate is big but my jaw is still not wide probably because of my masseters but soon I will finally be getting braces and a herbst appliance from my ortho plus since i have a recessed lower 3rd insurance might cover it because of my family history of needing air machines to breathe while sleeping so in the mean time im wondering how i can improve other things like my masseters and height while I wait to get the appliance in about a month Im 14 soon 15 and I cant get peps or even creatine for sm reason lmk what i can do in the meanwhile also is ashwaganda good for test boost.