38 AC at level 4?

[Westerner]

[replace with adamantine full plate (or even any other heavy armor) if you can afford it, that DR/- helps]
wear one of the lesser axebane (and sometimes spearbane) bracers from Korthos.
if you can get it, Furor's hide is one of the best protections at that level. If you get it, use it with the spearbane bracer. Furor's hide is like an improved axebane bracer.
keep a shield (possibly a tower shield) in your backpack, plus a one handed weapon. You will rarely use it, but when you want it, you will need it.

You will notice a lot of damage resistance gear and very little AC gear. That is because DR works well and AC doesn't.

This.

Adamantine full plate provides DR3 and is a simple, effective approach to defense at low levels. That's what I did for my wife's cleric. She wanted something that worked and wouldn't require a lot of switching items around or technical min/maxing.