I have a specific idea, but I don't know here to start

Question

Hi! My 25 year old daughter has had Type 1 Diabetes since she was eight years old. I used to create all kinds of tools for her on paper to track her finger poke sites, injection sites, meals and blood sugars. Since then she has used apps for better control, but they are always lacking in one way or another. I would like to build a logging, tracking, goal/reward based app using avatars and a room as the base for the reward system. I have in depth knowledge and a first person resource for what would be useful to an app like this, but I don't know which language I need to learn.
I learned HTML4 with a For Dummies book back in the early 2000s to build websites, so that's as much coding knowledge as I have (aka not much), but I did successfully teach myself with the book, so I feel like this is something I can learn to do with a little direction.
Thanks for any help and advice :)

Answer 1

@martin taylor, thanks for the advice and links! I'm not really looking to recruit anyone, though I can see why the collaboration tags might have made it seem that way, so I've deleted them. I just thought that someone knowledgeable here might have been moved to work on it with me. I realize that things have changed a lot and that I don't have a lot of knowledge to start with, but I'm really just looking for which languages to start learning to get to my end goal eventually. I was overwhelmed by the selection. I've decided to start with Java.
Also, the app would not be for clinical purposes, and as such would not have any serious, negative health impacts. It's just for tracking and logging, as a companion to other methods. It would help you keep track of all of the things you're supposed to log manually in a book, and reward you for keeping up with those things you're supposed to be doing. It's easy to fall off and my daughter has had a lot of trouble over the years. This is based on her needs and the needs of others like her.