To learn how to make good sound, you need to do a lot of this and always on normal equipment. Even following the tutorial videos completely, it is unlikely that you will be able to achieve what you want.
If you write step by step what is necessary, it will be something like this:
Learn the basics of sound engineering (books, videos, parsing tracks, the physics of sound is also useful to know)
To start putting knowledge into practice - downloading multitracks (fortunately there are a lot of them on the Internet, for example, on the Cambridge website). Many will say that you can make an acceptable sound on anything and I agree, but to do this, you first need to work on normal monitors or at least monitor headphones.
Mix, mix, mix. Stuff your hand. The more time invested, the better the mixing will be.
Work with people who understands more than you and learn from them (I do not recommend working with bad musicians who play crookedly, sing badly, read badly - it is better to send them adequately to teach the parts further).
Always remember that sources are MORE IMPORTANT than the mixing stage. Always try to find good quality samples and instruments (also, of course, depends on the style, but the question seems to be not about lo-fi).
I attached a playlist with the tracks I mixed, I have something to strive for :)
Divide the mix into three tracks, put filters, dividing them into low frequencies, midrange and high frequencies, and compress them separately. You can mix in the original sound. And rich and dynamic. More often analyze commercial tracks, and you will understand how to do it. I just thought of this trick
Well, you can start with the fact that foreign performers do not write music in fl studio. They have at their disposal a bunch of all kinds of equipment on which they work. If you want to make the sound better and denser, then buy a sound card (preferably external), use additional plugins and different compressors, this should help a little.
How-how, learn mixing and mastering. There is no such miracle plug-in where you press a button and mix, mastering, as well as selling a beat on Soundcloud and beatmaker.tv.
I will recommend a course from Ivan Savchenkov or Stanislav Melyashov. Paid, of course.