I've got three months left in the army. I want to do something that will be useful towards a computer science degree.
In the army base, I can't access a laptop. Only a smartphone with an internet connection and a Kindle.
Do you have any ideas?
There are a lot of books for learning Python (get something that is Python 3.x) that cater to different tastes. Find the one that looks the most “fun” to you so you stick with it.
If you have a mac, learn to use the command line. If you use Linux, learn to use the command line. If you use windows, setup WSL or a vm with Linux and learn to use that command line. There are a few books out there that are fun (I once even had one) but I can’t name any. The unix books I have now are specifically less fun and more nuts and bolts.
Why Python? Because you will be able to use it regardless of what else you do. I am mainly a JavaScript and Ruby programmer and I use Python for some things.
Why Unix? Because programming is significantly less painful for a lot of use cases on Unix.
Whatever way you go in IT you will be able to use the foundation you build if you know Python and Unix.
Problem is I don't have access to a laptop. It's not allowed inside the base.
Can I do these things with just a phone, internet connection, and Kindle?
There are environments for Python for Android and iOS, there are also web based ways to use an interpreter [1]. You can also get going with online tutorials instead of getting a book. Python has way way more options than just about anything else.
Considering your limitations you will probably not get beyond the basics of programming until you get your hands on a computer. Even if it is only a Raspberry PI. Entering large amounts of text or running even slightly larger scripts will be painful.
You will be better of trying out basic syntax to the point you understand it and only read the longer examples. One of the experiences of learning programming is entering longer texts and having them not work. Errors are usually small things and you need to be able to find them. In the beginning this is extremely frustrating and I don’t recommend doing this on phone.