Limiting Factors

I'm pretty new to this stuff and have been tweaking a few things each week. I know ventilation is pretty key, and that's probably #1, but I'm looking for some advice on the order of importance of limiting factors, roughly, and specifically, how important is humidity? Any help is appreciated. Peace.

Everything is important! Learning to grow is like taking a college course if you want to do it right. Humidity gets too high and you have issues. Temps get too high, issues.
Why don't we start with what are you currently working with?

Some might say water is the most essential compound, get the pH and cal/mag right and solve a lot of problems. Peace