"God gave him a vision" or "he saw a vision" (See: [[rc://en/ta/man/translate/figs-activepassive]])
# he saw the sky open
This was the beginning of Peter's vision. It can be a new sentence.
# something like a large sheet ... four corners
The container holding the animals had the appearance of a large square piece of cloth.
# let down by its four corners
"with its four corners suspended" or "with its four corners higher than the rest of it"
# all kinds of four-footed animals ... birds of the sky
From Peter's response in the next verse, it can be implied that the law of Moses commanded the Jews not to eat some of them. AT: "animals and birds that the Mosaic laws forbade Jews to eat" (See: [[rc://en/ta/man/translate/figs-explicit]])