It is the same with boxing. As long as you are watching the fighters, you can make your own predictions. Online prediction is also good, but it is still best if you already know how the fighters fight. Still, it is not always certain that the fighter you believe will win because this is dependent on their training, there are underdogs who can defeat the experienced ones, so bet with caution, and as I always say, in gambling, bet only what you afford to lose because anything can happen, even if you are sure that they will win but by the end of the game they lose.
I've tried to bet boxing already too, and luckily (just like in MMA) even if i haven't been watching the fighters there will be ton of youtube videos for catching up. And combining those with open detailed statistics i am in a good spot. I admit that it would be faster if i already knew everyone but you have to start somewhere and i am starting here.