Is there a way to make a frame fade in then out?

Yes, you’ve seen it occurring before. It is the act of using a for loop to iterate over the Transparency property of a Frame. Keep in mind, Transparency is a double that ranges from 0-1, therefore, we must ensure our loop iterates respectfully within said range. Using a float number, and these principals, we can increment and decrement the Transparency values to give the effect of "fading".

--// Basic application of theory
local Player = game:GetService("Players").LocalPlayer

local PlayerGui = Player:WaitForChild("PlayerGui")
local ScreenGui = PlayerGui:WaitForChild("ScreenGui")
local Frame = ScreenGui:WaitForChild("Frame")

for t = 0,1,.1 do wait(.1)
    Frame.BackgroundTransparency = t
end
for t = 1,0,-.1 do wait(.1)
    Frame.BackgroundTransparency = t
end