The raw files from that camera required at least Camera Raw 6.7. That means you need Photoshop CS5 or newer. You have several options. You could subscribe to the creative cloud photography plan and have the latest Photoshop and Lightroom. You could purchase Photoshop Elements. You could purchase Lightroom 6 (standalone version). Or, if you don't want to have to spend any money, you could download the latest DNG converter from Adobe and create DNG copies that you can use with what you have now.