I'd call it typical.
You need to have a lot of hands on work. Sippy cup out of reach, EXCEPT when he's drinking. Help him put it back on the table after he drinks.
The plate and stuff same thing, be right there, pay attention and don't let him fling the plate to the floor. Or just literally give bites off of your plate for another month and try the self feeding again.
The easiest way to correct this behavior is to prevent it in the first place. Keeping his food on a plate, even if you have to move it after every bite will make it easier for you to move the food out of his reach when he's full.
He doesn't know the plate etc isn't a toy, so remember that as well.