Ah I remember my first time with the Explorer as well. Went out in my yard and was embarrassed by it and had to go in.
I run mine in advanced mode. Manual Sens whatever is stable but around 22-26. Iron Mask at (-12) if the ground is clean I will sometimes run up to (-16 or is it down). I know a few of the settings on the SE are different than the II. I will often times notch out nails. I run volume max, gain 7-8, threshold 8-10.
Anyway there are people on this forum that know a lot more than I do. They will help you out.