If you are brewing with extract your best bet on water may well be Reverse Osmosis or even distilled. The water that the maltsters used to make you extract had, in theory, a desirable and controlled mineral content and alkalinity. using distilled water means, at least, you are using the wort the maltster intended you to use.
If the styles you are most interested in are Belgians and IPAs then the big areas for improvement right now for you include:
Hops, and how/when best to use them to get the results you are after.
Yeast, strains and their individual quirks and desires. Pitching rates, nutrient needs, and temperature targets.
From an overall perspective and an immediate bump in beer quality I would look into temperature control for your fermentation. this, along with yeast handling, will make a huge difference in your beer over not controlling these factors.
as brewers we walk a bit of a a tightrope with yeast. we want it to be happy so it doesn't produce stress compounds that we don't want, but we also want to keep in under control so it doesn't produce exuberance residue (I'm here by coining that term) that we also don't want.
Yeast want to be in a warm (80-90) environment with lot's of sugar. but they get overly exuberant at those temps and it gives me a headache (fusel alcohols). so we keep the temps in the low to mid 60's (for ale) and the yeast are happy enough so they are not overly stressed but no so exuberant that I wake up with a pounding headache the next day.
There are notable exceptions in either direction but this is a good staring point.