Start at 6 mos. If you turn your baby's high chair away from the table or remove his plate when he spits out or throws food & say "throwing means all done" in a low, calm tone, he'll stop doing it after consistent repetition.
If you yell, "don't do that!" without a consequence, he'll keep doing it. He can finger-feed well @ 9 mos, drink from an open-mouthed cup @ 12 mos & use a spoon @ 15 mos.