How do I make it so when someones mouse hovers over a brick...?

The player's mouse can be accessed (locally only) by game.Players.LocalPlayer:GetMouse(), so you can tell that the mouse is hovering over a brick by mouse.Move:connect(function()if mouse.Target==brick then end end). To position the gui element is to simply set it at UDim2.new(0,mouse.X,0,mouse.Y) because mouse.X and mouse.Y are the mouse's screen coordinates (in pixels).