As it moves up, it does not look smooth, and I tried making it move back down but "0,0,0" just restarted it in the default position, any help?
part = game.Workspace.Part
for i = 0,100 do
part.Position = Vector3.new(0,i,0)
wait()
part.Position = Vector3.new(0,0,0)
end

4 comments
I don't know how to make the part run "smooth", but the reason the part goes to default is because you're resetting it to point 0,0,0 after the wait().
Tweening http://wiki.roblox.com/index.php?title=API:Class/TweenService/Create
How about the movement why it is not smooth
Use Tween to fix it ,my friend.