Is there a master list of changes to 5e so we can keep up? For example, I think weapon damage is being changed from (as an example) d6+3 to d9 as I am inflicting 1 HP damage using a d6+3 weapon.
Is there any way to see our to hit and damage numbers?
Weapon damage has not been changed as far as I can tell, you're probably attacking something with resistance to your damage type (the Imps in the intro for example).
Also no, there is no "master list of changes" available as far as I can tell.
The combat log can be popped out in the bottom right of your screen and will give you access to some numbers