Well done Thats a fabulous pedal note off the bottom of the trumpet range.
yes you are on the right track
to go higher ie to a low trumpet note bring your corners inwards slightly go back and watch Greg
he is quite good at it !
Keep having fun! and maess about and explore.
all the best
Wish I had had acess to windworks when i was learning. Taught nyself all sorts of bad habits which I am still unlearning