You'd be better off with less watts and more speakers, like a 6x10. Gotto move more air to make more noise.
500 watts into 1x15 won't do it for you.
This is sort of like an investment. I would buy more cabs or just a bigger cab, if I had the money, but as of rn it's not an option. I want to buy enough headroom to buy an additional cab for later and of course a good enough head to sound good.
But thanks, although I'm aware that more speakers > more watts.