I've been lucky enough to collaborate with some talented sound designers and composers, and in working with them I've learned that I know nothing about sound design or composing, haha! It definitely takes a lot of time and practice to come up with something good, especially with free tools. If they aren't skills you'd personally enjoy practicing and learning, I'd definitely recommend teaming up!
And congratulations on your first finished game! Especially one that's this fun to play! You really did an outstanding job.