@Therunecaster
Apologies for the late reply! I only just saw your question. I has been a fairly bumpy but enjoyable journey.
I started by trying it out with booking just one lesson at a small local stables to first make sure that I would enjoy it. Many stables have some kind of ''have a go'' sessions where you can experience riding a horse for the first time with the instructor leading the horse around from the ground. You can also try a bit of trot that way.
My first lesson was a bit of an odd experience. They only had a small outside arena and it was raining slightly for most of the lesson. I was on the horse for way too long for a 1st attempt (almost 2 hours) so I was really sore for a couple of days after. The instructor led me around and then let me have a try on my own (walk only).
I then went to a bigger and more professional riding school and spent time with the basics of walk and trot with and without stirrups on several quiet horses. You can usually start with 30 minute lessons then when you body gets used to the process you move to 45 minute or 1 hour lessons.Although two of them ended having a little spook. I felt like I was not improving much after a few months so again I moved to a bigger place where I also learned the basics of cantering and I am still using these stables. They make you tack and untack your horse as well so you spend a bit more time getting to know them. The first time I cantered it was unplanned as my horse just took off after a fast trot in a group lesson...I have tried a couple of group lessons too but usually you get more out of individual ones obviously.
As you become more confident they move you to better and more forward horses and the make you do a test to put you on the next riding level.
I have found though that you do have to be quite resilient though as an adult rider. Some lessons/rides won't go well and other times will be magical. It also is not easy when you have a middle-aged body to do everything you need to do and to build the stamina. I must say many riding instructors are brilliants but others are not so used to dealing with adult new riders and one was actually really unpleasant to me. That instructor behaved like a bully (shouting at me that I was lazy and useless and they could not quite grasp that I might need to take a few minutes to get my breath back now and then) and I saw her bully other beginner adult riders too. Even the horses were scared of her which is never a good sign (I was on a horse and she came towards us and the horse literally jumped to the side when he saw her coming...). I complained to the school and to be fair to them they handled that quite well.
I did struggle with my confidence and still do but I am trying not to let that stop my enjoyment. I started with being quite fearful of horses if I am honest. I had some seriously grumpy mares who did not make it easy for me and you will probably have your fair share of horses who will suss you out as a beginner and refuse to move or completely ignore your commands and try to do as they please . When I was left on a pen with a horse on my own, the first few times my mind went blank!
I also did a hike in Hyde Park which is quite fun as you have to get the horses through the London traffic before you get to the park :)
I think it is like everything the more you do it, the more natural it becomes.
There are some great YouTube videos as well with tips for beginners. I spend a lot of time looking at these in between lessons.
My next goal is to be able to do group hacks.
Hope that gives you a bit of info on my journey!