Somehow this sentence sounds kind of pompous coming from a level 11 Duolingo student like me, so it needs a modifier. When I looked at Google to see how 'beag' would be transformed if tacked onto it, Google gave me 'beagán'.
But then the reverse translation of the sentence came back as: "Labhairt liom do theanga beagán" instead of "Labhraím do theanga beagán. "
If you want to say that you are able to speak Irish, you say "tá gaeilge agam". If you want to say that you actually DO speak Irish, in class, or with your friends, or on your holidays in Kerry, then you say "Labhraím Gaeilge" - it's not a claim of ability, it's a statement about what you actually do.