Just focus on the words you need in the situations which you need, the same way as you learnt your own language. Little by little, learning the most relevant words first, and always in context.

Sometimes dictionaries cause more problems than they solve. There's no point in trying to learn dictionary definitions, many of which refer to rare meanings of words in contexts which you will never find yourself in.

Forget the dictionary.  Think about how you learnt your own language.  When you were little you learnt words in context and as you needed them. When I was a very little girl I was delighted with my first doll's 'tea set'.  I didn't think 'Oh my goodness, I can't cope with this word 'set'. It can be 7 grammatical parts of speech and can have dozens of different meanings on its own, not to mention countless combinations of phrasal verbs!'  No, I simply absorbed the word 'set' in the context of something I knew and understood. That's the way to learn.

Some meaning is just in the context. 

Ex. The pool is filled with cold water. 

POOL is not used as biliard

We focus on the context! It's extremely easy to tell the difference that way.

Thanks for all comments, I appreciate all :)