How do I optimize my DataStore script?

Well for starters, for a cleaner look you could do this

local colvalue = Instance.new("IntValue",leaderstats)
    Trophies.Name = "Col"
    colvalue.Value = 0

for each of the attributes.

When it comes to saving you can make a table that contains all the things you want saved.

if GetSaved then
--GetSaved
else
local attributeSaving = {colvalue.Value,lvlvalue.Value,strvalue.Value,convalue.Value,agivalue.Value,intvalue.Value}

local DSService:SetAsync(uniquekey,attributeSaving)
end

you can do the same thing for the playerremoving event

@Nogalo:

Okay, I have made changes to my script based on your suggestions. It does look much cleaner and I can see how that method is much more efficient than what I had. Thank you :) However, I do have a few questions. In the top right leaderboard area, I now show 4 stats. "lvl, col, strength, constitution". I am curious as to why it only showed those values, and not agility, intelligence. Does the leaderboard area only show a max of 4 values? Secondly, in the script I set the "Value" of my abilities to 5, and the value of lvl to 1, thinking that would be the starting value. But they are all still showing up in the leaderboard area as 0. What does that value section signify?

@Goulstem:

I like the sound of that. How would I go about cloning the folder and where would I place it? Other than cleaning things up, is there any performance based impact from this method, for better or worse?

Thank you so much guys! Here is my newly revamped code, based on Nogalo's suggestions:

local DSService = game:GetService('DataStoreService'):GetDataStore('xxxxxxxxxxxxxx')

game.Players.PlayerAdded:connect(function(plr)

-- Variables
local uniquekey = "id-"..plr.userId
local leaderstats = Instance.new('IntValue',plr)
leaderstats.Name =  'leaderstats'

local lvlvalue = Instance.new("IntValue",leaderstats)
    lvlvalue.Name = "lvl"
  lvlvalue.Value = 1
local colvalue = Instance.new("IntValue",leaderstats)
    lvlvalue.Name = "Col"
  colvalue.Value = 0
local strvalue = Instance.new("IntValue",leaderstats)
    lvlvalue.Name = "Strength"
  strvalue.Value = 5
local convalue = Instance.new("IntValue",leaderstats)
    lvlvalue.Name = "Constitution"
  convalue.Value = 5
local agivalue = Instance.new("IntValue",leaderstats)
    lvlvalue.Name = "Agility"
  agivalue.Value = 5
local intelvalue = Instance.new("IntValue",leaderstats)
    lvlvalue.Name = "Intelligence"
  intelvalue.Value = 5

-- GetAsync
local GetSaved = DSService:GetAsync(uniquekey)
if GetSaved then
    colvalue.Value = GetSaved[1]
    lvlvalue.Value = GetSaved[2]
    strvalue.Value = GetSaved[3]
    convalue.Value = GetSaved[4]
    agivalue.Value = GetSaved[5]
    intelvalue.Value = GetSaved[6]
else
local assigndata = {colvalue.Value,lvlvalue.Value,strvalue.Value,convalue.Value,agivalue.Value,intelvalue.Value}
DSService:SetAsync(uniquekey,assigndata)
end
end)

game.Players.PlayerRemoving:connect(function(plr)
local uniquekey = 'id-'..plr.userId
local coltable = {plr.leaderstats.Col.Value}
local lvltable = {plr.leaderstats.lvl.Value}
local strtable = {plr.leaderstats.str.Value}
local contable = {plr.leaderstats.con.Value}
local agitable = {plr.leaderstats.agi.Value}
local inttable = {plr.leaderstats.int.Value}
local savedata = {coltable,lvltable,strtable,contable,agitable,inttable}
DSService:SetAsync(uniquekey,savedata)
end)

EDIT: I was able to answer 1 of my questions. My previous saved data was overriding the starting values. Once I renamed the datastore, all starting values displayed correctly.

also, I was tinkering around with doing something like:

local Attributes = Player.attributes:GetChildren()
    for i = 1, #Attributes do
        Player:SaveNumber(Attributes[i].Name, Attributes[i].Value)
    end

Would that be feasible? Less optimized/more optimized/roughly the same?