How do i fix load problems(animations and textures)?

It's most likely because, your script is moving faster than the amount of time for your animation and decal to load. This can be worked by using a sort of waiting sytem. Not wait() but, things like:

:WaitForChild()

or, what I mostly use is,

repeat wait() until blah blah blah == true (you don't have to use blah blah blah)

here's an example.

Local party = script.Parent
function re()
    while true do
        print(party.Name)
    end
end

re()

^^ this may or may not fail but, if it does then you could do

Local party = script.Parent
function re()
    repeat wait() until party -- This will make it so that the code won't run unless party is true.
        while party do
            print(party.Name)
        end
end
re()

You can also do

Local party = script.Parent
function re()
game:WaitForChild("Party")
        while true do
            print(party.Name)
        end
end

re()

or

Local party = script.Parent

function re()
game.FindFirstChild("party")
    if party then 
        while true do
            print(party.Name)
        end
    end
end
re()

When it comes to loading things such as decals and animations, you can use the ContentProvider service. This service has a function called PreloadAsync() that you can use to load in your animations.

local animTrack = --animation
local decal = --something
local cp = game:GetService("ContentProvider")

--The decal above should be an instance and
--not an id

cp:PreloadAsync(animTrack)
cp:PreloadAsync(decal)

--Animation and decal are loaded

The PreloadAsync() function also goes through all the descendants of an object which is useful for loading large amounts of assets at a time.