Hello! I was working on the platform for my game (That you see in the first picture) and my intent was to make it move smoothly and slow down the floors to fit flushed in at the opening of next floor. The problem is the script moves the platform really quickly and it doesn’t stop at the same spot every time. I provided a picture of my script and if someone could help me with this it would be greatly appreciated!
I was thinking of creating transparent parts and having the platform move to them through c-frame so if theres a way to do that too it would be cool if someone would let me know. 
You should use TweenService for smooth movement. Also you will be able to control the duration and the interpolation.
Here’s an example:
game:GetService("TweenService"):Create(Platform, TweenInfo.new(duration --[[ there are more parameters here that let you control more settings of the tween, read the dev hub page for more]]), {CFrame = CFrame.new(Target position)}):Play()
You can as well try to slow it down or add another zero before the 8. E. g: (0, -0.08, 0). This may slow it down and maybe work perfectly! TweenService is another option for you! you can use it for a smoother and better part moving!