Reading is something great for learning a language. Not enough but great anyway. We have to cultivate the other language skills: listening (oh listening, how much I have to improve here!), speaking and writing. Reading: you can do it you alone, on your own.
When reading fiction or nonfiction you will encounter new words: a nice chance to learn them or some of them… Try and guess the meaning of the new words, from the context, but also use a dictionary, maybe an online one.
Focus on those new words and try and guess their meaning from context, as I said. It is actual guessing but with some foundation, a somehow firm one: the context.
While reading you’re learning and acquiring too: some words will get stuck in memory, in an aware way and mode. You’ll be piling up new words! And you’re thinking in English! (Remember English is my target language). That language will be like a second one, part of your nature!
Each book means a firm step forward. As well try and learn some of those words you understood from the context, or you think you understood. Try guess meaning from context and from other words you already know in that tongue.
And retain the words you learn. Study the sentences where those words show up and appear. You’ll be making up a nice store of words into your memory. The more words you learn and the longer you read the more your memory will be able to learn and acquire words. It is worth the effort… / Photo from: YouTube. The picture is a nice illustration. It’s a mini-submarine. It might have to do with the plot of a novel...