This depends a bit on what you want to get out of this and how much effort/work you are willing to put in.
Doing a room EQ that actually works and makes it sound consistently better is quite complicated. There are commercial systems available but they tend to be complicated and expensive or tied to a specific product.
A really good freeware option to play around with is Room EQ Wizard https://www.roomeqwizard.com/
If you want to do this yourself, I suggest you break it down in a few separate steps that can be tackled individually
- Figure out how to make a good measurement in a room (noise, reverb, microphone, ADC, SNR estimation, etc.)
- Figure out what to measure (using the tools from step 1) that's representative enough of the entire room/speaker/listener situation
- Extract perceptually relevant parameters from these measurements
- Turn these parameters into some sort of correction that would move the parameters towards some perceptual target
- Design a filter and/or algorithm based on this correction
- Design the process/HW/system to actually implement and apply the filter or correction
All of these steps have been studied in detail and there is a fair bit of literature available on any of them.