You have opened the door to an excellent hobby that will help you build skills that can help you in every corner of life.
What brought you to make the purchase?
+1 - get training. Don't put a single round into that chamber until you have studied and re-studied trigger safety, muzzle safety, clearing process (making sure a gun is empty - that is what he was doing when "he looked the gun over" before handing it to you), field strip, cleaning, and reassembly. Do ALL of that - a dozen times or so - in order to learn the geography of your new purchase. Once you have some comfort level there, go to a range (with supervision), and get some instruction on how to make use of your new weapon.
Ask questions.
Be open to the answers.
And a note - you do not have an "automatic" pistol. "Automatic" means you pull the trigger and hold, and the gun will fire until all the bullets are gone. What you have is a "semi-automatic" pistol. Pull the trigger once, it fires once, and reloads itself. Pull the trigger again, it fires again and reloads again. But, it will only fire one time, each time you pull the trigger.
Study, study, study. There may be a quiz later
And, welcome to the family! Respect your weapon, and it will bring you hours and hours of enjoyment.