How do I code player specific scripts?

For E.G

If i want bloom to be active for only a player when he walks over a specific area. What terms do I use that only THAT SPECIFIC player that has WALKED at that area will see the bloom effect and the script shouldn't make the bloom active for everyone.

The best and quickest solution for this is to use FilteringEnabled and part hitboxes.

When a hitbox is touched, the server sends an event to the client that it then receives and creates a local bloom effect that will only be visible on the client.

Here's an example of a Server Script in a hitbox part that'll send the event to the client:

local Hitbox = script.Parent

Hitbox.Touched:connect(function(Object))
if Object.ClassName == "Part" then
if Object.Parent:FindFirstChild("Humanoid") then
local Player = game.Players:GetPlayerFromCharacter(Object.Parent)
Player.SomeEventsFolder.ActivateBloom:FireClient(Player)
end
end
end)

(Haven't tested)

Then you'll just set everything up, make a folder in StarterPlayerScripts with the event and a local script that will listen to the event and make a bloom effect when needed, also don't forget to edit the script above if you're using it, the remote firing line includes randomly picked directories.