So, you are learning a new instrument and you are learning a new genre. Why not separate these things for a little while? Start the new band using bass guitar, and aim to phase it out and replace it with the DB/EUB by say, July. Each rehearsal, you can play a tune or two on the EUB, gradually increasing its use.
In the meantime, your big challenge is to get the left hand together on double bass. This is not easy - you are building finger routine and muscle strength, honing your intonation and developing a consistent relationship to the instrument. Simandl is a great method. Explore it with a teacher in regular lessons, and if at all possible, using a bow. This is the quickest way - with the bow, there is no hiding, it's like a spotlight on your intonation and the shape of your left hand. Any imperfections are mercilessly exposed, and it will force you to adapt and perfect your left hand technique. IME, the hard way is ultimately the quickest and most effective.
The Latin Bass Book by Oskar Stagnaro is a great resource for learning about Afro-Cuban and Brazilian bass playing.