Hi,
The Bible says a few things about what the Millennium will be like. Everything else is unfounded speculation.
Firstly, of course, it will last for 1000 years. During this period Satan will be bound in the bottomless pit, and unable to deceive the nations anymore. Clearly, we are NOT in the Millennium at the moment!
Revelation 20:1-3: Then I saw an angel coming down from heaven, having the key to the bottomless pit and a great chain in his hand. He laid hold of the dragon, that serpent of old, who is the Devil and Satan, and bound him for a thousand years; and he cast him into the bottomless pit, and shut him up, and set a seal on him, so that he should deceive the nations no more till the thousand years were finished. But after these things he must be released for a little while.
Those of us who have been given our new bodies (i.e. the saints resurrected/raptured at Christ's Second Coming) will have bodies like Jesus' resurrected body. I would guess that they will exhibit the same properties as His - able to eat and drink, but not needing to, able to appear and disappear at will, move through locked doors, etc. (see Luke 24:28-43, for example)
Philippians 3:21: ... [Jesus Christ] will transform our lowly body that it may be conformed to His glorious body, according to the working by which He is able even to subdue all things to Himself.
Naturally, they will be immortal, sinless bodies.
1 Corinthians 15:51-53: Behold, I tell you a mystery: We shall not all sleep, but we shall all be changed— in a moment, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised incorruptible, and we shall be changed. For this corruptible must put on incorruption, and this mortal must put on immortality.
Some of the effects of the Curse will be reversed, but not all. The lives of those who enter the Millennium in mortal bodies, and their offspring, will be dramatically extended, but people will still die (eventually). The animals will be tame, not dangerous, safe for even toddlers to be around. Todays predator/prey relationships (e.g. the wolf and the lamb) will be rendered null and void. Animals will be vegetarian again, e.g. the lion will eat straw.
Isaiah 65:17-20: For behold, I create new heavens and a new earth; and the former shall not be remembered or come to mind. But be glad and rejoice forever in what I create; for behold, I create Jerusalem as a rejoicing, and her people a joy. I will rejoice in Jerusalem, and joy in My people; the voice of weeping shall no longer be heard in her, nor the voice of crying. “No more shall an infant from there live but a few days, nor an old man who has not fulfilled his days; for the child shall die one hundred years old, but the sinner being one hundred years old shall be accursed.
Isaiah 11:6-10: The wolf also shall dwell with the lamb, the leopard shall lie down with the young goat, the calf and the young lion and the fatling together; and a little child shall lead them. The cow and the bear shall graze; their young ones shall lie down together; and the lion shall eat straw like the ox. The nursing child shall play by the cobra’s hole, and the weaned child shall put his hand in the viper’s den. They shall not hurt nor destroy in all My holy mountain, for the earth shall be full of the knowledge of the LORD as the waters cover the sea.
Jesus Himself will reign from Jerusalem, and war will be a thing of the past. There will finally be true peace, and righteous government.
Isaiah 2:2-4: Now it shall come to pass in the latter days that the mountain of the LORD’s house shall be established on the top of the mountains, and shall be exalted above the hills; and all nations shall flow to it. Many people shall come and say, “Come, and let us go up to the mountain of the LORD, to the house of the God of Jacob; He will teach us His ways, and we shall walk in His paths.†For out of Zion shall go forth the law, and the word of the LORD from Jerusalem. He shall judge between the nations, and rebuke many people; they shall beat their swords into plowshares, and their spears into pruning hooks; nation shall not lift up sword against nation, neither shall they learn war anymore.
All of Earth will keep, at the very minimum, the Jewish Feast of Tabernacles. Those who refuse will be punished accordingly.
Zechariah 14:16-19: And it shall come to pass that everyone who is left of all the nations which came against Jerusalem shall go up from year to year to worship the King, the LORD of hosts, and to keep the Feast of Tabernacles. And it shall be that whichever of the families of the earth do not come up to Jerusalem to worship the King, the LORD of hosts, on them there will be no rain. If the family of Egypt will not come up and enter in, they shall have no rain; they shall receive the plague with which the LORD strikes the nations who do not come up to keep the Feast of Tabernacles. This shall be the punishment of Egypt and the punishment of all the nations that do not come up to keep the Feast of Tabernacles.
With Satan not around to deceive anyone for the thousand years, and a perfect, just government that rules with absolute authority, I imagine life will be pretty peaceful. However, sin will still be present in those with mortal bodies. People will still be sinful, or they wouldn't rebel against celebrating the Feast of Tabernacles, and they'll still be susceptible to deception from within and by others. They'll be open to Satan's deception once he's released at the end of the thousand years.
Revelation 20:7-10: Now when the thousand years have expired, Satan will be released from his prison and will go out to deceive the nations which are in the four corners of the earth, Gog and Magog, to gather them together to battle, whose number is as the sand of the sea. They went up on the breadth of the earth and surrounded the camp of the saints and the beloved city. And fire came down from God out of heaven and devoured them. The devil, who deceived them, was cast into the lake of fire and brimstone where the beast and the false prophet are. And they will be tormented day and night forever and ever.