I took a cross-country road trip a few years ago, and the journey was just as fun as the destination. Same thing applies when building your rack. Above all, have fun.
-- farkas
Love that analogy and applies to what I'm doing with my modular 'journey'.
You already have a lot of good advice from members who have been doing this for a long time (at least I think most of the replies are from those who have been doing it for a long time). I could never give you anywhere near the great advice you'll get from them, only that I am in a similar spot as you in that I'm very new to modular as well.
I can definitely attest to the advice of going slow. I originally bought a Hydrasynth desktop knowing it had some modular capabilities and that I knew I wanted to dip my toes into the modular world. I spent a good 3-4 months learning the Hydrasynth (and am still learning it today) and also reading up on modular, asking questions here and finally putting a rack out on the forum and letting members provide some feedback based on my goals with the system (which are to have a 'hybrid' setup where I can extend the capability of my Hydrasynth and also use CV Tools with Ableton going forward). I got some great feedback and now I'm 'gradually' building out my Rackbrute 6U (I also bought an Arturia Minibrute 2 at the same time as I bought the Hydrasynth). My idea was to use the Minibrute 2/Rackbrute 6U as my foray into modular...and of course the Hydrasynth. I haven't even really touched the Minibrute 2 yet...and that is probably the point of my post...this stuff gets deeeeeeep quick and you will want to spend time learning each of the modules capabilities. To emphasize that point, my first purchase was Maths...that was 6 weeks ago now I think...I'm still going through a tutorial that has like 22 examples of what it can do...many times I have to go back and redo one of them to remember what it did and how it did it...I'm still learning new ways to use it. A couple weeks ago, I got Quadrax and the learning curve just went exponential with not only learning what Quadrax could do on its own but how I can use Quadrax and Maths together with my Hydrasynth to do some crazy stuff. I can't even imagine going out and buying my intended complete rack and trying to learn everything...it would be overwhelming...heck, it is overwhelming as it is...lol.
I just may be an idiot and not able to pick up on stuff as well as others, but that has been my path so far and I'm glad I'm doing it the way I am....somewhat slow and steady...you will be tempted (as I have been)...and you will see a module you want in your rack that someone has for a good price (as I have)...and you will buy it (I've done it twice now with Warps and FX Aid XL)...but try to hold back somewhat and give yourself some room to breath and learn...I haven't even plugged in my FX Aid XL into anything yet because Warps, Maths, and Quadrax have kept me up into the morning hours multiple times and I still am just scratching the surface.
I'll stop rambling now, but just wanted to add a comment from someone who is also new to the game...these guys give great advice...take it...go slow, research, download VCV rack, ask lots of questions, seriously consider what your goal(s) is/are with modular and then ask for advice on what to build. You'll be glad you did...I am.
JB