Programming revision help

It sounds like you know a programming language already, so to improve your coding the best way is to just practice. I'd recommend starting a big coding project where you set out to make some sort of complicated program and learn what you need as you go along. You can then improve your code over time. I'd recommend learning Git and how to use GitHub as it's a kind of industry standard way of storing programming projects, and if you build up a good portfolio it will help you in the job market as well.

I'd also recommend improving your programming problem solving using Project Euler. It's a series of over 780 mathematical problems which get progressively harder which you use your coding skills to try and solve. They range from basic things like finding primes and Pythagorean triples to very complex problems. If you don't do anything else then I'd at least recommend taking a look at Project Euler just because of the way it develops your algorithmic thinking.

Hope this helps.