When he scratches your hand, say "oww oww owww" in a high pitched voice to let him know it hurt you. Same thing if he bites. I've read that's how momma cats and sibling kittens communicate that a kitten has gotten too rough. It's possible your kitty was taken from his mom too young and was never taught how to "play nice".
Also, if/when you can hold him, clip the tips of his claws. Until you're comfortable with nail trimming, just clip the very tip, as if you clip too far down (into the quick), it will bleed and hurt him. Clipping off the sharp tip will at least protect your hands until he learns to keep his claws in. If he won't let you hold him long, just try to do one claw at a time, whenever you can. How To Best Take Care Of Cat Claws
Also, if/when you can hold him, clip the tips of his claws. Until you're comfortable with nail trimming, just clip the very tip, as if you clip too far down (into the quick), it will bleed and hurt him. Clipping off the sharp tip will at least protect your hands until he learns to keep his claws in. If he won't let you hold him long, just try to do one claw at a time, whenever you can. How To Best Take Care Of Cat Claws