When starting w eq, I found 2 things super helpful:
1. Reading about what sounds are where in the freq spectrum. EQ cheat sheets are a thing:
https://cheatography.com/fredv/cheat-sheets/eq-tips/ I can't find the other ones that I used, which were more graphically oriented.
2. Playing around with a spectral analyzer/editor. Nothing like selecting a freq range visually and listening to just that range to teach you where various instruments are, and vocals, in your own recordings. Also helps for finding where boom and mud are in the bass, or strident/brittle high end..
PS: TDR also make my favorite sounding compressor to use with Audacity, Kotelnikov. Simple to use, too. Fish Rabbi turned me on to it and now I use it for parallel compression on most recordings' 16/44 version. Makes a huge difference for ear buds, car, and other non-optimal listening.
PPS: You need a high quality reference playback system to learn eq. You have to be able to keep one of the sound variables stable or changes are confounded and you'll have a hard time connecting cause to effect. Doesn't have to be crazy spendy. An external DAC w headphone amp, and some reasonable headphones can work. I primarily use massdrop x akg k7xx red edition, and then check w massdrop x sennheiser hd 58x jubilee headphones. Both under $200. Of course I also check on living room system and in care. Learn how a reference system sounds, and work from there.
Have fun with it, give yourself tons of time to play, and it'll start to make sense.