It's pretty simple to do a basic tune up yourself.
First "assuming you have a pc" is to download and install c cleaner. www.ccleaner.com/ This can remove temporary files on your computer and also easily lets you kill start up programs on it. Start up programs are thing that boot up when your computer boots up and generally slows it down over all. You usually can delete most of the stuff on this list.
Assuming you don't already have your ram or memory upgraded to the max that is another easy "ish" tune up. There are a lot of online videos and instructions of how to do this yourself if you feel like it.