Lowrance is pretty much plug and play for the most part.
I 800 on the side scan, swapping to 455 when I down scan. 800 will be darker but I usually have the sensitivity set at auto +2 maybe 3/4 depending on water clarity.
On the sonar, it depends on what you're looking for, what type of bottom you're in, and what type of contour. 83 will be a broader range, good for finding say suspended fish, larger structure, and that signal is also stronger and usually works better on plane keeping contact with the bottom longer for me anyway. 200 will be a smaller cone, works better finding fish say near a drop off, around large rocks, or in structure like a brushpile.
On the bow I prefer to turn sensitivity up until the background has small vertical lines that create a fuzzy look in the background.
One other tip, the structure overlay is usually turned on from factory. Turn that off...it's a pain IMO.
2014 Bass Cat Sabre
2014 Mercury Pro XS 150 - 68.3 MPH @ 5,750rpms
MotorGuide 24v 75lb
Lowrance HDS 7 Touch Units
Abu Garcia Revo SX/STX Reels