I get 2 errors when i click a button and why does a function activate itself?

So I have a script that will load Online mode when the online button is pressed, but that function happens before i can even press the button! also when loading "finishes" it won't let me click another button "in debugging". what happenes is that after it finishes loading, it says "15:33:40.351 - Attempt to connect failed: Passed value is not a function, 15:33:40.362 - Script 'Players.Player.PlayerGui.StartupScreen.StartupLogic', Line 61" and then it says "15:33:46.988 - attempt to call a nil value" when I click a button(the active one, online button)

Here is the code, and if you could please help me, ive done all the debugging , my self (that i can, till i gave up) and it doent show me.

Here is the Console:

15:33:40.351 - Attempt to connect failed: Passed value is not a function 15:33:40.362 - Script 'Players.Player.PlayerGui.StartupScreen.StartupLogic', Line 61 15:33:40.363 - Stack End 15:33:46.988 - attempt to call a nil value 15:38:23.153 - Auto-Saving... 15:43:23.220 - Auto-Saving...

Here is the Code:

--define all variables
local OnlineButton = script.Parent.Frame.OnlineButton
local StoryButton = script.Parent.Frame.StoryButton
local RandomModeButton = script.Parent.Frame.RandomModeButton
local Console = script.Parent.Frame.Console

local OnlineAvaliable = game.Workspace.OnlineAvaliable.Value
local modes = {"story", "online"}


--functions

function clearConsole(textToClear, clear)
    if textToClear and clear then
        textToClear.Text = ""
else 
    print "Error 01, unable to clear"
    Console.Text = "Unable to clear, Error 01 \n"
    end
end
function onClickPlay(doLoad, mode)
    if doLoad and mode == modes[1] then
        print'Loading story mode'
        clearConsole(Console, true)
        for i = 1, 10 do
            Console.Text = "Loading Story Mode."
            wait(0.8)
            Console.Text = "Loading Story Mode.."
            wait(0.8)
            Console.Text = "Loading Story Mode..."
            wait(0.8)
        end
    end
    if doLoad and mode == modes[2] and OnlineAvaliable == true then
        clearConsole(Console, true)
        for i = 1, 10 do
            Console.Text = "Loading Ejected Online."
            wait(0.8)
            Console.Text = "Loading Ejected Online.."
            wait(0.8)
            Console.Text = "Loading Ejected Online..."
            wait(0.8)
        end
    end
end

OnlineButton.MouseButton1Down:connect(onClickPlay(true, modes[2]))