I have some minor suggestions regarding the punctuation in this passage. Where you have used ellipsis (the three periods), they should be separated by spaces: Once upon a time . . .

Just before a quotation, it’s customary to place a comma: . . . he noticed a sign that said, “Caution . . .”

Finally, punctuation such as a comma should be placed within quotation marks: “. . . Do Not Enter,” but . . .

I’m curious what this passage is for.

–Matt

Also the ellipses after ‘Once upon a time’ is unnecessary.

So it could go like this:

Once upon a time a young boy was walking through the forest. He noticed a sign that said ‘Caution–Do Not Enter’. But the boy entered anyway and was eaten by a rabid grizzly bear.

Same story, just three sentences to separate the ideas.

here let me help,

Once upon a time, a young boy was walking through the forest. The Boy noticed a sign that said, “Caution — Do Not Enter,” notwithstanding, the boy entered anyway. As a result, he was eaten by a rabid grizzly bear.

[x grammer is everything my friend.