15/08/2022
OK...if you want to be a DJ....you need to not only learn the tools of the trade, but also the basics of AV and sound...the in's and out's. There are many videos on youtube to demonstrate connections, but let me boil it down to you in a nutshell...
Basic controllers usually have 4 connections.....there is the Master outputs, usually RCA (white/red) where red is right, and white is left outputs. You have a USB connection to your laptop, usually USB-B (square) to either USB-C (newer) or USB-A (the flat one). If you have a USB-C laptop, then go on Amazon and get a USB-B to USB-C cable and save yourself an extra connection and dongle. Lastly you have a headphone jack for cue headphones.
If you are using an iPhone or iPad, then you need an appropriate dongle or hub that gives you the USB connection and also allows for power.
As you get more sophisticated, you might get additional inputs (red/white) for turntables or other devices like CDJ's and you can often switch between the input and the computer playing. You can often gain Microphone inputs which are usually 1/4" plugs, so you need the appropriate dynamic microphone with that built in, or an appropriate cable to use your choice of a dynamic microphone (dynamic does not require further power to function). You can add an external mixer which I will mention in a bit. You might also have additional outputs such as a booth speaker etc.
For the most flexibility you should invest in an external mic mixer...at the most simple level something like the Mackie ProFX4 will give you 2 mic inputs, the input for your controller and extra Line inputs via RCA (red/white) which can be either an external CD player, or mostly anything using a 3.5 to RCA cable, the headphone output of a phone. Be careful with newer phones as you need the headphone adaptors.
The external mixer gives you the ability then to mix the Mic and Sound before feeding your speakers, often you can add basic reverb/echo to mics if wanted, basic EQ (adjust highs and lows) and you have an AUX/Monitor output to drive a booth speaker.
Finally You can take the Master out from your controller straight to speakers, or you can take the output of the mixer, if using one, straight to speakers.
This assumes you are hard wiring everything with cables for the best quality/performance. You CAN use bluetooth to connect to wireless speakers, but you have less flexibility, less quality and often deal with latency, and also you will need to still hardwire a microphone to the speakers.
I am not going into any more detail about connecting speakers, Active vs. Passive speakers, XLR vs 1/4 cables or Line vs Mic level, but they are all important to know as well...for instance, certain connection types have a distance limitations and are more prone buzz/humm, and others are the difference between a very low level signal vs a more powerful signal, which when connected incorrectly not only sounds horrible, but can cause damage.
Lastly, may I just ask you all to be kind to your wires :). Learn the proper way to wrap wires to get the most our of your investment, because you can have the best equipment around, but if your wires fail, and you don't have backups (you all have backups of your necessary cables...right?) you are dead in the water.