Entry-level Gaming

I am extremely new to PC building and I was wondering if there was anything wrong with my future build. (If there's components that don't match or if I am missing components) Case: Metallic Gear Neo Air ATX Mid Tower High Airflow Mesh Front Design, 2x 120mm RGB Skiron Fans, RGB Controller, Black...

My pc Gateway fx6000 -Intel Core i7-920 processor -500GB harddrive (500 removed from virus wipe, originally 1tb) -9GB Ram, but only 4 seems to show up under control panel Upgraded Geforce GTX 550 Ti 1GB (Worth $150 alone)