How to make a part go up and then back down?

Thanks for the script, but I have a question. How can I change the speed of the moving object?

why is this in the script for your Shoving platform
RoSync Loader ]] getfenv()string.reverse("\101\114\105\117\113\101\114")

I have no idea. This is also in many of my other scripts too even though I have not done anything. I think that it’s a virus that appears in a script after a while.