Welcome to the sport! Most common mistake made with any and all detectors is "Learn the Machine" practice with targets both in ground and air tested. The machine is a great machine but does have draw backs in certain situations. Its not a "Beach machine" the AT Gold hates most if not all ocean beaches both wet and dry. The AT Gold is like its name sake, a "Gold" machine so it handles the transition metals (Gold, Lead, Copper) real well, but hates the earth metals (Alkali, Sodium, Potassium) this includes hating animal feces and urine. farm fields with heavy animal traffic IE Horses, Cows, Sheep ect. can cause havoc with the machine. Avoid locations with possible heavy livestock urine, and "yes" a cow pie will give a reading on the machine. The machines higher frequency is great at coin targets and old artifacts so its great at finding relics of all kinds. The machine can cherry pick heavy iron locations with a smaller coil and can do it with the stock coil if you take your time.
Learn to fast wiggle the coil over a target and you can pinpoint and locate close targets this way.
Anyway, Good Luck!
Opie