coi
Maybe the main concern is actually "How to spread out the language so that I have many people to speak/learn/make errors with?"...
I don't have stats on Lojban usage, but it seems rather a niche (correct me if I'm wrong). And maybe this is what you feel when you ask if language is learnable.
I feel like the small dispersion is the main drawback of the language, unfortunately. Lojban is obviously worth more Lojbanists! ;)
co'o