>> how do I go about doing this "Measuring" <<
Well, either you do the work learning to use OmniMic or REW or something similar, or you don’t. There are no special tricks; it just takes doing it a few, or a few dozen, times. There’s quite a bit online, especially for REW. Besides the mic and software, you need a standard mic stand (about $35 last I looked).
Measurement is cheaper than most audio things (especially exotic cables) and has a better payback than many audio things, but it has a little DIY in it and is not something one can just buy and enjoy. It’s not for everyone. But I think you’re probably up for it.
If you have a Windows laptop available, I’d recommend OmniMic2, which I found easier to set up and learn than REW. But thousands of audiophiles use REW every day.