How should I...........?

I think that the best way to improve your English speaking is to speak with as many native English speakers as you can. Idapted.com has a program that will pair you with an English speaker but I'm not certain how much it costs to be a part of their program. Take English classes and get instructional tapes. I'm taking Italian classes and in addition to class, I watch Italian movies and read Italian newspapers. For words that you don't understand, there are plenty of online dictionaries that you can make use of. Best of luck to you.