I've never played pen and paper RPGs before, so I don't know pretty much anything and the amount of detail is a bit overwhelming. Our DM is inexperienced as well, so I can't really be sure if they know the mechanics that well either.
Anyway, in the starter campaign a lot of simple enemies have AC of 16-18, with a boss being at AC 21. Most people on our team do not have a combat bonus, so even for a garden variety goblin they have to roll pretty high to even hit it, and for the boss only 2 out of 4 people can even try to hit him, for others even a natural 20 is too low.
Intuitively this feels a bit off to me, but having never played such games I have no idea if this is normal, or if we screwed up character creation and didn't take some important skills or such (we used PCGen to create characters)
So is this normal balancing or is something actually wrong?