If on a mac, the no-brained would be GarageBand, but I’m assuming you’re on Windows. A lot of students I teach start off with FL Studio or Sony Acid, then move on to sequencing on Reason or Ableton Live. The former two take very little musical knowledge and are primarily loop editors (you build songs by arranging the individual parts as short “blocks” of music that loop and sync together automatically to a master tempo).
The latter two are a bit more sophisticated as they let you go deeper into manipulating loops and adding your own loops with synthesizer instruments that are a part of the software.
If you’d rather start off just blending pre-recorded full tracks, then you’re seeking more of a virtual DJ program. The good ones usually cost quite a bit and require hardware if you want to mix with controllers that emulate authentic DJ hardware (mixers, turntables, etc.). A good entry-level system to look into for DJ’ing is M-Audio’s Torq software-which can be purchased with a controller surface for about $129 for the system. You would also need a sound card or box (USB audio interface) that has 2 pairs of stereo audio outputs (one for listening to one “deck” on headphones and cueing, the second pair of outputs for connecting to a PA it stereo system for amplification).
Let me know if this helps or if you’d like more direction…also it’s helpful if you know what your computer system’s specifications are…some programs require a certain minimum amount of memory and disk space to run. Good luck!