So everyone here picked up the Ashbory as a second instrument (you already played bass)?
Krellmusician,
Does moving to the dark side of the band, where the
percussionists live, give you the willies?

As an experienced musician, your chances of mastering the fretless Ashbory are infinitely better than a total noob's. You've already climbed the hill to understanding music theory.
No doubt, from here on in you'll catch yourself trying to tune out everything but the bass lines of songs that you perform and listen to. There are a ton of "Learn to play Bass" books available. Pick a couple that have some good audio samples to practice. A little
Korg metronome is a good idea too. You are now going to be very much responsible for keeping everyone else in the band on tempo. That's your new job.
Going forward... Play with other musicians at EVERY opportunity. Also, having a sense of humor will help a lot. You're going to get a lot of razing...until they hear what your 'bory can do.
You're going to have a lot of fun. Enjoy!