I took advantage of GIK's free room analysis about 6 months ago and have continued to be impressed with the results. I took a few months before I decided on a specific acoustic company to research and educate my self on room acoustics in general. I used all free on line resources, especially via Google and You Tube. I found out there's a wide variety in the quality of advice being offered for free on the internet, ranging from poor quality and virtually worthless to surprisingly high quality and valuable.
But don't worry, you'll quickly and easily be able to determine which sources are knowledgeable, experienced, trustworthy and worth investing time in learning from and which are not, it's fairly obvious within a few minutes of reading or listening. I found this video, interviewing Anthony Grimani, to be especially useful and a good place to begin your edification:
https://www.youtube.com/watch?v=raAyF5ksbkk&t=40s This guy has produced other videos that I found interesting and useful. I suggest you take notes no matter which expert sources you decide to trust and learn from.
Good luck,
Tim