Spain? Nice. The low tech magazine is operated from Barcelona. I'm occasionally envious about the amount of sun and the temperatures in late autumn while it's cloudy and rainy here in Germany...
Yeah. I'd pick something to start with. Depending on how much you want to delve down, it's quite some amount of time you can sink into every individual field. And if you're like me and constantly try too much at the same time, you'll either get overwhelmed/disappointed from time to time because there isn't much progress. Or end up with the drawer of unfinished electronics projects we all have 🤣
But that shouldn't stop you. And that's mostly something you should keep in mind while starting out. Luckily we have tons of tutorial videos, online documentation and stuff available to us. If you start with some pre-made stuff and already existing projects it'll make it considerably easier to get some results early on.
I mean you do you. I've learned programming from textbooks and I think this is the way. At least it teaches you things properly and why you do something instead of just copying code. It takes some patience, though. I don't know what learning type you are. I think computer stuff and social degrees require a bit different ways of thinking. But it's not rocket science. Just have fun and explore. If you experience major setbacks or want to get a bit more serious, consider going to the library and get a book on Python or find one online (or a course).
Hosting stuff on your Raspberry is also rewarding. But I'd really consider starting with something pre-configured. All the sys-admin stuff (when starting from scratch) takes a good amount of knowledge with several topics, and some experience with the specific tools and frameworks. Other people might disagree but I think it's less rewarding than for example programming and you'll get a steep learning curve early on. On the other hand it's super useful to run your own internet services. And we have the projects available that make it easier.
So, happy tinkering... Keep us posted in case you start another low-tech blog coming from Spain to us. And don't let any complexity stop you 😊