how to select player 1, player 2 one by one?

First of all, game.Players:GetPlayers() does not accept any arguments, so giving it 1 will not give you the 1st player. It returns a table, so if you are certain you have at least one player (which I think is almost always the case), you can do game.Players:GetPlayers()[1] - or, better, assign it to a variable first:

local players = game.Players:GetPlayers()
print(players[1]) -- or do whatever you want with it

Of course, in your case you don't want to do something with all players, not just the 1st one that GetPlayers happens to return.

So, see how your script has a bunch of repeated code? That's a clue you need to use a for loop (for syntax, see https://www.lua.org/pil/4.3.4.html). Also, you need to understand tables/lists, so here's a quick demo (just in case you didn't know, everything after a -- is a comment):

local list = {} -- make a new list
list[1] = "hello" -- "hello" becomes the first item in the list. One could also say that we're assigning the value "hello" to the numeric key "1".
list[2] = "there"
print(#list) -- "#" is the number of items in a list. It only works if you use integer keys (like 1, 2, etc), and don't have holes (ex if you do 1, 3, 5, it may not work correctly).
print(list[1], list[2]) -- will print hello there
for i = 1, #list do -- repeat the loop for each item in the list
	print(i, list[i]) -- print the index 'i' followed by the value. First time it will print "1 hello", the 2nd time "2 there"
end
list[2] = nil -- removes the item from the list. You can also use table.remove and table.insert to remove and add/insert items.
print(#list) -- will print 1

Now we could do this simple script:

local pos1 = Vector3.new(-62, 2.522, 31)
local pos2 = Vector3.new(63.766, 8.1, 141.166)
wait(123)
local players = game.Players:GetPlayers()
for i = 1, #players do
	local player = players[i]
	player.Character:MoveTo(pos1)
	wait(50)
	player.Character:MoveTo(pos2)
end

It's your script, but fixed to use for loops and GetPlayers correctly. However, it has these problems:

• It accesses player.Character without checking to see if they have a Character (though actually I'm not 100% sure that there's a time they don't - but it's better to be safe) - even if they have a Character, their character might be dead (and about to respawn), so we should at least check that.
• If a player leaves, you'll still attempt to move them around. If they're "in focus", you don't automatically advance, either.
• It only works once (though this might be something you want - maybe you Clone the script when the round starts).
• Maybe you want to randomize the order of the players

I don't tackle the 2nd point, but here's an improved version:

local pos1 = Vector3.new(-62, 2.522, 31)
local pos2 = Vector3.new(63.766, 8.1, 141.166)
local selectedPlayers = {} -- dictionary of players selected so far
local function playerIsSelectable(player)
	-- Only allow a player to be selected if they are alive and haven't been selected yet
	local humanoid = player.Character and player.Character:FindFirstChild("Humanoid")
	return not selectedPlayers[player] and humanoid and humanoid.Health > 0
end
local function selectRandomPlayer()
	local players = game.Players:GetPlayers()
	local validPlayers = {}
	for i = 1, #players do
		local player = players[i]
		if playerIsSelectable(player) then
			validPlayers[#validPlayers + 1] = player
		end
	end
	local selected = validPlayers[math.random(1, #validPlayers)]
	selectedPlayers[selected] = true -- record that we're selecting this player
	return selected
end
wait(123)
while true do
	local player = selectRandomPlayer()
	if not player then break end -- either selected all the players or no other players are ready/selectable at the moment
	player.Character:MoveTo(pos1)
	wait(50)
	player.Character:MoveTo(pos2)
end