You did good. My first time trimming a beak, the hen jerked at the last second, causing her beak to slip farther back in the clipper, and the result was I hit the quick full-on.
It bled like a fire hydrant. Not only that, hitting the quick on a beak hits the most sensitive and most abundant nerves on a chicken's body, causing immense pain.
Trimming a beak should be undertaken only for the most serious of reasons, and using the utmost care and caution. It's definitely a two-person job.
I commend you again for getting advice and guidance before attempting to trim your chicken's beak.