Where to go next? - 11 Aug, 2020

Hello.  New to the group and offshore fishing.  Been at it for about 2 months and learned much.  Been spending most of my time at MR, 9 mile and other reefs in the area.  Have done fairly well for a newbie and want to get out further.  Ledge???  Maybe.  MR is around 70 feet deep.  How much farther would I have to go to get more, bigger and better action?  100-150ft range?  Once there, do I drift or spot lock on the trolling motor?  Slow trolling is always an option for Kings.  Are there fish symbols on a chart plotter for those depths.  Any advice would be helpful.  Thanks.