Hi!!
If you're only low rank, theres no full armor set that gives auto guard but you can gem a five slot armor with 5 auto guard jewel.
Let me just say though, Auto Guard is good early game to assist newbies on weapons with shield but AG will hurt you more than it will help you most of the time later on in game unless you have proper skills and items. I suggest if you're going for the lance class your armor skill targets should be Sharpness +1, Sharp Sword, Sharpening Skl Inc, Guard +1/+2
Guard Inc, Constitution +1, Reckless Abandon +1/+2/+3, heck even Attack Up is much better than Auto Guard later on.