Hi Job, and welcome to WriteWords
Naomi's advice is very good. Another thing which helps is to start trying to notice what you're reading as you read. When something's really effective, why? How are they telling the story? (because articles are stories too, of course) What's the writer doing with his or her words and sentences? Look for the real detail of how they do it: it gets your eye in for grammar, punctuation and syntax (how words are arranged in a sentence) as well as stretching your writer's mind with more different ways of expressing yourself.
If you want to try out a range of different kinds of writing, and begin to learn how writers think, and how they then turn what they're thinking into coherent words, you could have a look at
The Creative Writing Coursebook. You can either work your way through it, or pick and choose what interests you.
If you're in London particularly good places to look for courses would be
Morley College or
City Lit, both of which are very central, and have a wide range of courses for different levels and experience.
Emma