That's understandable. I plan to break down those details in tooltips eventually. The gains from those stats vary based on the weapon you have equipped so it's something I'll show in the Gear tab.
Generally, you shouldn't swap weapons early on, so I adjusted the first trader to stop selling the weapon you aren't using. If you have some Valor, it can help you catch up train another physical weapon, but it's probably still not optimal in the demo at least.
For meta-progression, it's going to change/develop a lot. I agree it's not super rewarding right now.