Hi there @drrkbeats
Sorry for the very late reply, hopefully it gave you some time to watch the tutorials I mentioned in my PM, I list them back here for other members as well.
@big_phil touches great points in his reply, so that already helps, basically it will have to do with gain staging and balancing your sources, the point with metering is that there's a huge difference between the RMS and peak levels that the DAW meters can pick up and display and the perceived loudness depending of your audio source, so that's where using a VUmeter can be handy, or any other meter that provide a loudness measurement.
Levels are building up, per channel and per track and depending of your audio source and especially if you have low end frequencies, you can quickly end up with faders all over the place to compensate inside the DAW.
So next to using a VUmeter or other loudness measurement solutions, it's a good habit to start controlling your levels right at the source : so that could be the output of a soft-synth or effect plugin, or placing a utility device right after the plugin when you don't have direct control on the plugin output itself. But yes, anything that lets you control the source level, before it reaches the track output and fader.
The idea is to have your faders quite balanced against each other, it makes gain staging and re-balancing the all mix much more easier then. Let's say you have a soft-synth output peaking close to 0 Dbfs ( in peak and RMS ), if your only control is to reduce the track fader to compensate, you're gonna end up with faders all over the place with huge differences and it quickly becomes hard to Mix because of perceived loudness, tiny adjustments for some sounds with low frequencies will reflect as huge boost for example, so it's better when you can have more even faders levels across all tracks before hitting your Busses and Master.
Hope this helps