Wizards are pretty frail. If you want access to better armor you can take one multiclass level in Cleric to gain armor proficiency (how much you get depends on what subclass you choose, but you can literally gain everything by picking the correct ones)
EDIT: Also, at level 3 a lot of characters die pretty quickly. It's not unusual. You get MUCH more staying power once you hit around level 5+.
Okay, I rolled a 14. What's that mean?
Hsu
That you're a cheater. This is a 12-sided die.
Chan