Translation
And it shall be, in the last days,
Go to footnote numbersays THEOS, I will pour forth my Spirit upon all flesh; and your sons and your daughters will prophesy
Go to footnote numberyour young men will see visions and your elders will dream dreams,
Paraphrase
It will come about, in the final age [the age of the Messiah], says THE CREATOR AND OWNER OF ALL THINGS, that I will lavishly impart my Spirit to all types of people, then those lacking authority will speak divinely inspired revelations of the mind of God, the young and inexperienced ones among you will see appearances [of angels with special messages from God], and those with experience and authority will see visions [from God] during their sleep.
Footnotes
1: “In the last days”:
In various places in the OT, including Joel 2:28-32, quoted by Peter, the phrase “in the last days” had reference to the age which would be introduced by the coming of the Messiah. Therefore, everyone who has lived since the death and resurrection of Jesus, and definitely since the coming of the Holy Spirit at Pentecost, has been living in “the last days.”
2
“to prophesy” can mean to speak a divinely inspired utterance, to speak forth a spiritual truth that people need to hear, or to foretell details of something that will happen in the future. Actually, all of these should come to a person through divine inspiration. Although we usually think prophecy means to foretell an event in the future, that was the least common usage of this word in Bible times.