Welcome new guy... former paramedic and FF here. I'm not actively flying, but I follow things on here.
There's a lot of focus on finding the right instructor/environment and that is important. But that is half the battle.
You have a lot of things working in your favor already - your work schedule gives you time to fly several times a week, which is good - the more frequently you fly the quicker you will attain proficiency and the less money you will spend getting the license. If you fly once a week or less you will spend much time re-learning the pyschomotor skills associated with flying the plane, rather than progressing.
While I may be stereotyping, I see public safety professionals as not easily excited/panicked, generally exhibiting good judgement, able to navigate (read maps) and comfortable talking on the radio.... all things that may take more time with folks without that background.
The cockpit is a terrible classroom for theory - its noisy, its cramped and its expensive. During your downtime at work (and on days off) you can stick your head in books that will prepare you for the theory/knowledge side of things.
There are several texts I recommend based on my experience over 12 years ago in getting my ticket.
Textbooks by Kirchner for the private, instrument and advanced/commercial
http://www.kershnerflightmanuals.com/. You can buy them other places besides that link. The latter two are overkill for a minimal level of proficiency for the Private Pilots license. I feel these are very well written texts and recommend them without reservation.
Gleim test manuals - this is a test bank database/book. These are the types of questions/exercises that the computerized knowledge test will encompass. Some people memorize the test bank - I'm not that kind of guy, I recommend understanding the rationales behind the answers.
Jeppesen textbooks are nice, very well written and somewhat pricey. I'm not sure there is much value added over the Kershner books but there is nothing wrong with them at all.
While it is not necessary to attend a formal ground school, it is essential to learn the material, and self teaching is acceptable for most of the information involved. When you choose an instructor validate the book info with them and apply it to the act of flying the plane.
The FAA requires 40 hours to be able to get your private pilot. I've heard average numbers thrown around of it being 60-70 hours before getting an endorsement to take the practical test. I solo'd at 17 hours (very late compared to average) I was endorsed at 42 hours and passed by the end of 44 hours (very early compared to average) - I'm not bragging, but using that to bookend the following:
I completed ALL the ground schooling on my own and took my written test before I ever took my first lesson (I had some intro flights from a pilot family member but nothing loggable). This is atypical for many many students, many do it in parralel with flight training or in a batch right before solo. I read and understood the curriculum completely, knew how to read the map and what the symbols meant, how to get and interpret weather information, etc.
I had actually started reading the instrument text because of the in depth information it gave on navigational systems. That is overkill but thats how I roll. I suspect in your job, a fireman may be expected to perform as an engineer, and an engineer may be expected to perform as a company officer when needed. Knowing the next step in the knowledge chain never hurts.
Fly 2-3 times a week. You will spend less on training in the long run. Plan on an hour of flight time and a 2 hour block of time at the airport.
Buy a local "sectional" chart and green AFD book and teach yourself to understand what the information in them means. Get a cheap cardboard E6-B whiz wheel.... its a circular slide rule that helps do time/distance/fuel use calculations and also to calculate crosswind components. All of these items can be obtained in the form of Apps or subscriptions for your handheld smartphone, but that can come later. Learn fundamentals using tools that dont rely on batteries, and move up to gee-whiz devices later.
You dont need a $1000 headset, but give some thought to a step or two above bare bones bargain basement. Noise fatigue is real. I started with some cheap bottom shelf av-comms, then added gel seals for comfort, then later added my own do-it-yourself noise cancelling inserts. If you decide you are going to continue past your first few lessons, a comfortable noise cancelling headset is a sound investment. The cheapo you start with makes a good guest-headset when you graduate to carrying passengers.