medyo malawak nga yung tanong / kailangan pero don't be overwhelmed. Unti unti lang, hindi kaagad matututunan un. For starters, try searching "sound engineering basics". Maraming lalabas na results and try reading/understanding them. This should hopefully give you the basic concepts.
With respect to eq and mixer, a good place to start is the manual of the mixer (kung available). Kahit siguro paano may nakasulat dun na description nung mga knobs/faders/etc. Then isa isang i-search yung terms na hindi naintindihan.
Tapos, depende sa mic'ing technique and sa placement ng inputs, apply lang yung "frequency spectrum" concepts nung individual drum items sa mixing. Cymbals are normally on the high end of the frequency spectrum. Snare is somewhat in the middle and the bass in the low. So, depende sa gusto mong maging tunog and depende sa mga mics na nakakabit, pwede mo adjust ung mga eq ng baway mic or inputs para ma-achieve mo ung gustong sound. If you want a "trebly" sound, increase the highs. Kung lows naman, then yung lows.
yung drum mic'ing, isang malaking topic din yan.. he hehe...
unti unti lang maiintindihan din yan.
And syempre, sabi nga nila -- "push buttons / turn knobs / slide faders" -- essentially, experiment ka tapos tignan mo ano nangyayari sa tunog. Based sa result ng experiment mo, magkakaron ka ng idea ano ginagawa and ano nangyayari sa bawat change. Doing and playing around helps a lot in learning
good luck.