"create a level system with xp that changes players health and the damage of the players weapon"

-- script for adding XP 
local Players = game:GetService("Players")

function addXP(player, amount)
    local stats = player:WaitForChild("leaderstats")
    local xp = stats:WaitForChild("XP")
    xp.Value = xp.Value + amount
end

Players.PlayerAdded:Connect(function(player)
    local stats = Instance.new("Folder")
    stats.Name = "leaderstats"
    stats.Parent = player

local xp = Instance.new("IntValue")
    xp.Name = "XP"
    xp.Value = 0
    xp.Parent = stats

local level = Instance.new("IntValue")
    level.Name = "Level"
    level.Value = 1
    level.Parent = stats

local health = Instance.new("IntValue")
    health.Name = "Health"
    health.Value = 100
    health.Parent = stats

local damage = Instance.new("IntValue")
    damage.Name = "Damage"
    damage.Value = 10
    damage.Parent = stats
end)

-- script for updating levels, health, and damage 
local Players = game:GetService("Players")

function updateStats(player)
    local stats = player:WaitForChild("leaderstats")
    local xp = stats:WaitForChild("XP")
    local level = stats:WaitForChild("Level")
    local health = stats:WaitForChild("Health")
    local damage = stats:WaitForChild("Damage")

while true do
        wait(1)
        if xp.Value >= (level.Value * 100) then
            level.Value = level.Value + 1
            health.Value = 100 + (level.Value * 10)
            damage.Value = 10 + (level.Value * 2)
            player.Character.Humanoid.MaxHealth = health.Value
            player.Character.Humanoid.Health = health.Value
        end
    end
end

Players.PlayerAdded:Connect(function(player)
    player.CharacterAdded:Connect(function()
        updateStats(player)
    end)
end)