In the top right hand corner of my screen it says my apple ID instead of my name.
how can i change it to say my name?
To change your full name (the one you see at the top right corner), open System Preferences > Users & Groups, and you will see a box to change your name.
If you have to change your username, this is difficult, but I think you can do that
In my system preferences there is no users and groups part. In the account settings it says my full name is correct, it just comes up with my ID instead for some reason.
In Snow Leopard, it doesn't appear "Users & Groups". In this case, you have your Apple ID as your username. Make a backup of your data and see > http://support.apple.com/kb/HT1428
If i upgrade to mountain lion will i be able to change it easier?
Mountain Lion will upgrade your actual version and it will keep using the same username, so it won't work. The easiest solution is to create another user with a different username, but you can try the link I have given you
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