In your case, I would start with the things you like - Bitcoin and Nostr and look which programming languages are there to work with.
1. You can look for open source Bitcoin or LN mplementations and check what languages are used there. Then pick the project you want to contribute and learn the language as well as contribute to the open source project.
2. You can also build Nostr apps, focusing more on the frontent, since you have some interests into arts (photography, music, etc.), so design part can also be good in your case. I would go and ask around Nostr developers, which languages they use on a daily basis and then having a list decide which one to take.
When you have the exact languages, share a list of them and I am happy to help you pick the one and maybe guide you to the courses (like Udemy) that could be beneficial for you.