i think is the best thing to start with brakes, a lot of tricks are way easier with them, from basics like fire hydrant and decade to the most advanced barflips variations.
you can learn everything brakeless but theres no advantage for me, some people thinks that if you learn something with brakes it will be harder then to do it brakeless but it's not true.
i know people that for their ideas took them off too early and now after years they still haven't learned a lot of basics.