My baby is 2 months old and I've just started to take off his mittens to let him adventure with his hands, but he keep sucking his fist once the mittens are off. Even his fingers are red from the sucking. Is this okay and if not ok, how do I prevent him from this constant sucking?

I believe this is a normal behaviour as it happens to all my 4 babies. Babies are just curious about themselves and wanna explore more. Actually suckling is a form of comfort for them too. You don't have to worry at all. Do take note and make sure that the don't put their fist inside their mouth.