Not beach: hi trash, auto sensitivity, all metal or relic mode. black out leverything except 36,37,38,39. this will give you all US coins except most zinc pennies and all silver. if you want to add 14,15 you can also hunt nickels without too many pulltabs(mostly 16). If you want to dig zincs add the mid 30's and if you want brass add on down thru 32. These are GENERAL guidelines and anything can show up pretty much anywhere.
Beach: as above except all metal and wide open. you will dig trash, but thats where the gold hides (all over)
Yes, you will be passing up finds with lots blacked out, but at the end of the day you wont have pulled out any hair. As you gain confidence, add more numbers/range. By most accounts it takes 40-60 hours on the machine to get decent with it. I have hunted mine for several years and am still getting better as I experiment with it.
Other general thoughts for a new Safari owner (mostly oriented to coins and jewelry):
Ignore targets that flucuate in tone and number: they are crushed cans, or pieces of cans. Listen for 'strong, solid, repeatable' tones.
Believe your depth indicator. Mostly anyway. If it says 4" and at 8" you havent hit it yet, stop- its a can or something large. (unless you want to dig relics, of course)
And here's a piece of advise you will ignore or mostly ignore: Do Not pay attention to the display numbers. Listen for the tones and remember what you dig for a given tone.
Read thru the posts here. I know its a lot to do, but it will pay dividends galore. You are not the first to ask this, nor the first this month.