Sounds like you had a good first trip to the range, all things considered!
This is a good fundamentals video on grip:
https://m.youtube.com/watch?v=7jVbvwWtWIA
With your gun unloaded and no round in the chamber
*Important***
(First!!! eject the magazine!
Second!!! Rack the slide and eject the round if one is in the chamber.
Third!! Visually confirm there is no round in the chamber.
Fourth!!! Use your finger and touch the chamber manually to confirm there is no round in the chamber.)
** always ALWAYS do the above steps in the above order. If you flip steps 1 and 2, the gun will still be loaded. NOT GOOD!!**
Point the firearm in a safe direction always.
Then, with the gun still unloaded and the magazine out of the gun and away from you, bring the slide forward into battery.
Now, with the empty gun pointed in a safe direction, first line up the sights. You want all three dots lined up evenly. Then squeeze (don't pull) the trigger slowly. Try to keep the gun as level as possible through the trigger break.
Rack the slide and try again.
Do this until you can pull the trigger without jiggling the gun left or right.
Something you might try is placing a quarter on the slide and see if it moves while you practice your trigger pull.
Once you get the hang of it, plan your next range trip and see how you do.
Btw, Lenny is a salesman but he is also a fantastic shooter with good info, so please bear with.