Start in standard mode...pro mode gives you a lot more noise and info but can be overwhelming when your not used to it...you have plenty of time to switch to pro mode after you learn the machine...you will find plenty in standard mode...experiment back and forth with both modes and you will see what I mean...good luck.
It was the first machine i have put over 100hrs into, pretty awesome little rig and i were you, from experience try and get an "AT Pro International" - i would say start in pro zero mode with Iron audio ON, discrimination 0-25 so to include some small small gold items, and try to get a 5x8 cool as it's much lighter, way better separation, still a DD coil... It's a good machine
Dig anything 45 and up repeatable within +/- 5 if slight jumpy. Don't be afraid of junk, gems hide sometimes and you never know what will come up. Best of luck!.
If you are digging for coins, listen to the machine, if it is a solid bell tone with 52 VDi it is likely a nickel, 81-82 most likely a dime, 86-87 most likely a quarter, the tones will solid ding, no breakup or hiccup in the tone. In the 80's if it whines it is most like a pop can or can top