Whether or not you want to hear from me again, I am going to set some facts straight:
1. I am not a young lady. I am an older, knowledgeable man who has always been willing to try and help someone. But, the individual seeking help must have the right attitude, and exhibit the appropriate behavior, along with being receptive to assistance. Obviously, that is not the case with you.
2. I do understand when you say "Mavericks is not on my computer". What that specifically means in your case is that currently, Mavericks is not the operating system (OS) that you are currently running under. It is Yosemite. But, to start the process of installing any OS (assuming your machine qualifies for it), that process begins with a file called "Install OS X "OS Name"". So, I was asking if you still have the file entitled "Install OS X Mavericks" on your machine. If not, then one can go to the App Store, click on "purchases", and see which software one has downloaded from the App Store. For me, I do see the 4 Mac OX X Operating Systems Lion, Mavericks, Yosemite, and El Capitan which I had previously downloaded from the App Store (in addition to some other products). So, I can go back to the App Store and re-download any of them.
But, it's obvious anything I try and say to provide assistance falls on deaf ears.