my user folder says i have more gb than i actualy do

Download from the Internet OmniDiskSweeper and Grand Perspective (both free) and open them. They will show all of your files and the respective sizes. This should allow you to determine exactly what you have on your Mac and where it is located. Transfer to an external HDD the files you do not want on your Mac or delete them.

Do not forget to empty trash. Only then is space allocated for additional data.

Ciao.

Most likely in your hidden ~/Library as email messages, messages (especially pictures sent via messages), and iPhone/iPad/iPod Touch backups.

Finder -> Go -> Hold the "Option" key -> Library

Take OGELTHORPE advice and use one of the utilities (I prefer OmniDiskSweeper).