Last night a DJ...

Those things are no longer made, but they are excellent.

If you don't really need to be a great DJ, no complex mixing, just playing a good selection of music... then these things are the size of a phone and fit a thousand FLAC files and will do auto-beat matching, fade ins, beat calculation, etc. But mostly they're just easy to cue up the next and cross fade.

Primitive skills you need to be a DJ:

• Reading a room and pick the right record for them (how to get people dancing, keep them dancing, give them a break by getting others to dance at times, etc)
  
• Which songs go together from your selection as you can't always go into Blue Monday
  
• Cross fading
  
• Monitoring and cueing up
  
  

Intermediate skills:

• Not just reading a room but knowing the crowd in advance and predicting a lot of the evening (this is intermediate because until you've mastered reading a room you'll screw up predicting it)
  
• Beat matching
  
• Mixing seamlessly for close matching tracks
  
• Complex fading (holding both tracks, moving between them)
  
  

Advanced:

• Totally seamless mixing over long periods of time (loops, effects, fades, holding a moment far long than the track would normally allow)
  
• Creating new tracks and moments from the records you have, splicing together, etc
  
  

For the kind of music the clubs I ran played... the indie rock and alternative... I never had to progress beyond the basic and still some of those clubs were very successful (not RPM, which we got bored with). One of my friends took the same music and was intermediate, mixed in House music ad took himself to advanced, he played the BBC 6 Music NYE party and is pretty well established now and living comfortably from DJing with the travel and lifestyle that comes from that.

But just learn to read a room at first, focusing on tech is the wrong answer for a good while. A laptop and a collection big enough to go in multiple directions is better than a pair of expensive decks that you're going to struggle to use.

So long as you can monitor a track whilst playing another... you're good.