I have seen some tutorials on Udemy, it is true that they are good.
I don’t know much about fluid simulation…
I know something about fluid dynamics… about conservation of energy, Bernoulli, Reynolds number and stuff related to physics. I am an engineer 
But I really don’t know anything about rendering fluids. I just know that it needs a lot of processing power.
Surely here you find people who know a lot about this topic.
If you know object-oriented programming (I know you know) and some design patterns. You will realize that Unreal integrates all of that.
Then learning unreal will be much easier for you… you don’t need to spend money. Everything is perfectly organized.
You just have to know how to use everything at the right time and in the right place.
Good luck!!