A minor thing, not meant to be a discouragement because I love when people reach out to new things. I love that you are reaching out to American Football and falling in love with it, and never will my intent be to stop that. I am here to help, as I've done before.
It's a Field in Football, not a Pitch. Baseball is also played on a Field. Ice Hockey is play on a Rink. Field Hockey is played... well, on a Field, as the name suggests. Basketball is played on a Court. And Futbol is played on a Pitch (except Americans will still say Field, because often we can be unaccepting of origins).
So as we wouldn't say a Basketball Game is played on a Field, and we wouldn't say Ice Hockey is played on a Field, we shouldn't say Football is played on a Pitch (and us Americans that do, should not say Futbol is played on a Field).
It's a very minor thing, but learning those minor things will have a greater impact. Just as you said "A defender false starts". I am sure you meant 'off sides'. Because you are learning and they are similar. It's the details, the little things. So getting 'Field' right will help you pay better attention when discovering other little things, like the difference in Offside and False Start.
Much like if I were learning Futbol from you, you'd want to impact upon me the little nuances of Futbol and their importance. You'd want me to call a Wing a Wing, a Striker a Striker... because that is what they are, and getting those fundamentals helps when things start to get more difficult.
I hope this in some small way helps, at the risk of being taken in the wrong way.