First of all, 41 is not too old for anything!
Never to late to start, and it is easier than ever to learn how to code.
I've mentored several "Experienced & Wise" students as they begin the journey of learning how to code. I tend to have a mix of older (64 was the oldest so far) and younger students, and I am always struck by how thorough my older students are when it comes to documenting and understanding what they are learning, and how it fits in with what they already know.
As you are learning to code, it is great to have a few apps that are just for playing around and tweaking, often referred to as a "Breakable Toy". Something you can mess with, break it, and learn by putting it back together. It is also easier to get help on these kinds of apps, because you aren't worried someone is going to steal your secret idea. They are a perfect playground.
When it comes to building a real app that you are passionate about, it is worth considering if your goal is to do the coding, or to just be the owner of the app, and outsource some parts of the development/design, etc.
Most of my students fall into just those 2 camps:
1. Developer: they want to become a developer (either working for someone else, or working on their own apps), and they are interested in investing in their tech education (books, courses, trial & error, etc).
2. Business Owner (with Tech skills): they want to build a business around an app (they may do some of the initial coding, but their main passion is seeing the thing launch, so they might outsource some tasks get them done faster/better).
This Tech/Biz student, sometimes cited as "Become your own technical co-founder" expands their technical skills enough to get their idea off the ground, prove out the market, get customers, build a team, seek funding, etc. Their goal is to launch a business, and they get the technical skills to help accelerate the progress, but being a developer is not their end goal.
There's nothing that says you can't switch from one goal to the other (especially once you get into it a little more), but if you already have a strong feeling, it might help you focus how you invest in your education.
Which kind of conference would you rather attend? One that focuses on development and programming techniques, or one that focuses on business, marketing, launching a startup, etc?
Look in to local groups, dev bootcamps, online groups, etc. and figure out what type of coding you want to do, and where you might get the support you need.
On the business side, the "Lean Startup" tools are designed to help you validate your business concept, tackle risks head on, engage with potential customers, and keep you focused on building something the market will really respond to. (the most common reason business fail is "Lack of Customer engagement" - aka "No one cared")
Best of luck to you!!