Advice to Newbies

1. Read Get Better Sound
2. Use the search feature before posting the same questions over and over again (I'm guilty)
3. Consider how you consume sound and where; may influence your design choices

@baclagg Gotcha! I agree, of course! 

Given a bad enough room, though, your advice could apply. Because if the room is terrible enough, one might never know what a given set of speakers sound like. In that case, some kind of pre-treatment of a room -- even a carpet or some absorptive furniture -- would be necessary before trying out speakers.

@hilde45  I was assuming that a newbie has made the initial plunge and purchased a set of speakers. Then, after some time, starts longing for better sound. This is where the REW comes in. Before falling down the rabbit hole, make sure your current dissatisfaction isn’t room related.

EBM giving some solid advice again.

hilde45 offers the correct response. I think that treating a sound room before the actual system is placed there is a reverse way to go. Different systems (especially speakers) have characteristics of their own. And how they interact with the room will be different.

Room acoustics and treatments is very important. But it should be a "fine tuning" step and not an initial one.

OP, good post but what do newbies test their room with if they don't have speakers to play the REW tone sweep with?

My own process was to get speakers I liked a lot and then tested to see how the room could be improved to accommodate the speakers. 

Get a least 6 Stillpoint Apature panels for your room get the best ASAP.