How do i make a brick give money when touched but don't give money again until i reset character?

I don't exactly understand what you mean by one player, but as for not working till they reset their character that's rather easy. Each time someone dies, the whole model of their character is destroyed and they respawn. We can use this to our advantage. When the script is activated, put some kind of tag onto them, for example, it can just be a simple BoolValue instance, then name it something like "MoneyBrick". Then in the script, if it detects the name of this instance in the player than don't give them any money.

Okay, so almost an hour of trying to get this to work, I've managed to successfully do it (Could've taken less time but It's currently 4am and I'm super tired). So I previous made the answer without the Timer that you wanted, and I've been working on the Timer. And I finally got it to work. Here's everything you'll need.

You will need a:

1. Script(x2) Both Their Parent's will be in the part.

2. A Timer(NumberValue) Which will be stored in the part also. Name it TimeUntilAvailable (Keep it's Value to 0)

3. A Bool Value (Which will become true if the part is touched.) Name it isTouched.

4. Another BoolValue (Which will become true if the player has reset, and will be false if they have not reset.) Name it CharacterHasReset

5. And finally, another Script which will create the CharacterHasReset Value inside of the Character. (Script's Parent will be StarterCharacterScripts)

So here are all the scripts:

Script 1, Timer Script:

local TimeUntilAvailable = script.Parent.TimeUntilAvailable

    while true do
        wait(1)
        if script.Parent.isTouched.Value == true then
            TimeUntilAvailable.Value = TimeUntilAvailable.Value + 1
            if TimeUntilAvailable.Value >= 20 then
                TimeUntilAvailable.Value = 20
            end
        else
            TimeUntilAvailable.Value = 0
    end
end

Script 2, Detecting if the Character touched the Part:

local function onTouched(hit)

    if hit.Parent:FindFirstChild("Humanoid") ~= nil then

        local Touched = script.Parent.isTouched

        local Character = hit.Parent

        local CharacterHasReset = Character.CharacterHasReset

        local TimeUntilAvailable = script.Parent.TimeUntilAvailable

        local Player = game.Players:GetPlayerFromCharacter(Character)

        local Stats = Player:FindFirstChild("leaderstats")

        local Coins = Stats:FindFirstChild("Coins")

        if Touched.Value == false and TimeUntilAvailable.Value == 20 and CharacterHasReset.Value == true then
            Coins.Value = Coins.Value + 5
            CharacterHasReset.Value = false
            Touched.Value = true

            TimeUntilAvailable:GetPropertyChangedSignal("Value"):Connect(function()
                if TimeUntilAvailable.Value == 20 then
                    Touched.Value = false
                end
            end)
        end

        Player.CharacterAdded:Connect(function()
            CharacterHasReset.Value = true
        end)
    end
end

script.Parent.Touched:Connect(onTouched)

Script 3, Creating the CharacterHasReset Value. (Insert Script into StarterCharacterScripts)

local CharacterHasReset = Instance.new("BoolValue", script.Parent)
CharacterHasReset.Value = true
CharacterHasReset.Name = "CharacterHasReset"

Also there may be a simpler way of doing this but I over complicate things when I'm tired. Anyway, Hopefully it all works for you. It should as I just tested and it worked perfectly for me, but if it didn't work for some reason, post a comment and I'll try and help you fix it.

Basically what this will do is it will check if the Parts touchable by checking the Bool Value we added to the Part (isTouched) and it also check if the Timer is equal to 0. If the Timer is equal to 0 and the part is equal to false, using false because we first need to check if it's the value is equal to false then set it to true right after so it wont run again. And we're also checking if the CharacterHasReset is equal to true, if it's equal to true then that means the Character has reset, then they can collect the Coins, if it's not equal to true and it's equal to false then they cannot collect the coins 'til their Character gets respawned, which they'll need to die for that to happen.