He's normal.
He is young.. .they STILL have the "startle reflex". As he gets older, he will grow out of it. They all do.
You would try and put him in a swaddle sleep sack.
But his limbs will still move/startle... but as least he will be in a sleep sack. But at a certain point, he will get too old for that too.
Him grunting and making noises... well all babies do that. If you let him be, he may very well just fall asleep himself. Just see. If he is not crying/screaming... then let him be. He may just need to soothe himself. My son was like that... he was a GRUNTER and made a lot of "noise" before actually falling asleep. But he was fine and not crying/screaming. It was just his way... of falling asleep. I also KNEW his sounds... so I knew if he was fine or not, needing me or not. And sure enough, he would fall asleep on his own, self-soothing, after making his grunts and noises.
Or, under his mattress, put some rolled up blankets to elevate one end of the crib mattress. Don't put it under him because it would be a safety hazard... so put it under the Mattress. Or they have wedges, to elevate a baby's head.
all the best,
Susan