...I haven't received a response to either my email or voicemail (both about 3 hours ago, which was during their open hours.) How long do they generally take to reply? This will be my first time with a provider so not sure if I need to say/do something to get a response (I am RS2K verified, although I didn't mention that yet)

It's been said over and over.
First asking for help on here under an alias gets you no where, get it.  
Second, mentioning that you are rs2k when initiating contact is the surest way to GET A RESPONSE!  Please spend you hard earned time on the newbie board so mistakes don't frustrate not only you but everyone else.
I'm tired.

Welcome to the hobby. Briar is absolutely right in all cases.
- Alias = no PM responses, and usually few posts.
- RS2K, P411 and a few others are golden door openers. They provide acceptance and credibility you cannot match on your own, especially as a newbie.
- The Newbie Board is a treasure trove of good information. Search for posts from Sinful Sinthia (Sinful 1). She lays it out for newbies in a clear, concise manner. She is a great help to hobbyists. She's also a great companion, but that's another story.
- TER has great resources available. Learn to use them.

His first message did not go through on my voicemail and I was out at dinner when he emailed.  I do not use a mobile email device for everyone's safety and discretion.  We're in touch now.

Nick -

...turns out I was just a little impatient haha. Got a callback from Nick who was very helpful...and yes, mentioning RS2K helped

Michelle's service is one of the best anywhere in terms of running an agency the right way. And Nick is very professional. But he's also very careful to protect their ladies. They have many years of fine service so those in the know knew you'd hear back from Nick. Happy hobbying.

You blew your cover, dude.