Hi timpaton,
We have students in their 70's learning to kite so no worries starting to learn at 47!
The learning process will be slower compared to learning in your 20's. I was a slow learner even in my mid 20's with lots of board sport background. Learning in poor conditions and challenging locations, it took me 1 year before I could get up and ride the board. It took me another 2 years before I could ride upwind well, do transitions and start learning my first jumps.
Being time poor and living far away from decent kite spots are major obstacles for you to learn and progress, but it can be done if you are determined and have lots of patience / perseverance.
Wind quality on lakes is often poor compared to ocean locations. You also have to consider getting some light wind specific equipment since you probably will be dealing with lighter winds in general (large size single strut kites and large twin tips is what I recommend).
I personally kited on lakes a lot as a beginner (including lakes in NSW) and I can tell you that it's much more difficult simply because winds are usually a lot less reliable and also because it can be hard to find a safe place to rig your kite, launch and land it. Learning to kite in lighter / gustier winds can be a lot harder compared to stronger / cleaner winds such as sea breezes. I was learning on a 16M kite by the way.
I recommend you start by reading this blog post from our website:
www.kitebud.com.au/how-many-lessons-do-you-need-to-learn-kitesurfing/Your background in sailing will only help a little bit but I'm sure you already understand that learning this sport will be completely different and require a whole new set of skills.
The truth is a lot of people kite solo, myself included. It's definitely not the smartest thing to do but if you are healthy you can mitigate the risks by taking smart decisions and getting some really good training (lessons). For example, if you are in a shallow water area with cross-on shore winds where other people can see you, it's a lot safer than going into deep waters with no one around.
You have to be very careful with YouTube videos. Self-launching and self-landing are skills that are very rarely performed / demonstrated safely. The videos often lack context and don't demonstrate what can go wrong and how to deal with things going wrong when self-launching or self-landing doesn't go as planned. This is the same issue with lessons nowadays where not enough is being done to show you how to handle the problematic sitautions.
Self-launching is something you should only worry about later on in your progression i.e. once you are able to ride upwind and do transitions.
Self-landing can be performed very safely (regardless of the wind conditions) as a complete beginner. We show this to our students in the very first lesson. You can check out these techniques in our online courses:
www.kitebud.com.au/kitesurfing-online-courses/ It's hard to get quality lessons nowadays as most lessons are done in shallow waters with a focus to get you up and riding as quickly as possible. This means skipping over important steps that can make you a safer, more independent and more competent kitesurfer. You can read more about lesson quality here:
www.kitebud.com.au/how-good-were-your-lessons/Hope this helps
Christian - KiteBud