I’m a big fan of REW software. I agree with others that there is a learning curve so, to get the most out of it requires some time and effort on your part. I enjoyed the learning process and the SQ of my system benefited from the effort.
Audiogon is not the right forum to discuss measurements. AVNirvana (where you get the REW software) is a good place to ask “how to” and "what does it mean" questions. Gearslutz (pro audio) is a good place to read about acoustic problems and solutions. They generally don’t answer questions from the 2 channel hobby crowd but every question you can think of has already been asked. Search the forum.
You want a smooth frequency graph but I find the distortion graphs and the time domain stuff (ETC) more useful. Finding solutions in the time domain helps resolve problems in the frequency domain. Of late, I’ve been trying to lower the T30 values per Floyd Toole’s recommendations.
Lots of info in these books: “Sound Reproduction” by Floyd Toole. “Master Handbook of Acoustics” by F. Alton Everest and Ken C. Pohlmann.