Most DJ controllers are sold with a special light version of the DJ software. These versions have few channels and effects. If you want to use more functions, you should buy a full version additionally. There are many different software programs that you can use with a controller. The three most popular programmes are Serato DJ, Virtual DJ and Traktor Pro(the latter is only bundled with Native Instruments DJ controllers). Your choice does not depend on your experience level, but on your DJ style and your expectations of the software.
Traktor and Serato are the industry standard when it comes to DJing. Serato DJ is more preferred by turntable and hiphop DJs and Traktor Pro is more popular in the techno and house scene. Ableton Live is a DJ and production software in one and is also used by professionals like Chris Liebing, Richie Wartin and Dubfire for live performances. The software costs about 50 to 200 euros, depending on your equipment. On the internet, you can find YouTube videos or articles that can help you choose, for example, the differences between Traktor Pro and Serato DJ. It's best to think about which DJ software you want to use before you buy.