Even if you were on the older side that'd still be very doable if the interest and time available is good. Late 20's is just too young though, you are definitely not too old to try this.
My advice is after you pick a language that suits your interests (say C++ for bigger/efficient projects, or python for data science, JS for simple web stuff). Most languages nowadays have extremely similar syntax and functioning, so once you've learned one learning a second is much easier.
After that what worked for me and a couple peers was both doing simple puzzles from websites like Project Euler and following that language's community preferred tutorial/book. You don't have to actually get the puzzles solved and lots of them need some tricks, but at least it'll get you acquainted with the language syntax and functioning. For me the starting book was "The C Programming Language" which still reads fantastically nowadays.
The main issue I've found for self-learned programmers is the awkward phase between knowing how to make self-contained small programs and having the know-how to participate in production scale ones. The available material out there is very sparse in this area and if you don't reach out you could find the experience very lonely and frustrating.
I think one possible solution is to pick some open source project you already are familiar with as an user, and trying to participate in that community and help with some easier issues like bugfixes. I think that helps learn a lot of good practice just through sheer exposure and interaction, without having to pay for courses or the pressure of an actual job. For instance if you like games and C++, there's Godot or if you like Rust and Lemmy, there is Lemmy itself.
Also don't fall into the trap of trusting accreditation too much. Programming is mostly learned through practice and a lot of courses don't bother teaching important things like how to build a proper workflow. I've seen people come out having written multiple papers on AI but that still didn't know how to use git.
And most importantly, don't be afraid of making mistakes and take all the time you need. Those are the most important parts of learning. Feel free to ask more questions!