Make English your daily language
The first thing you should do is to make English your default language. Start the conversation in English and only English. You must not get deterred by the fact that you do not know the language well and hence people may laugh at you, because those are the people who will soon compliment you once you develop your expertise and fluency in English.
Read
Start reading English novels, English magazines, and English newspaper. Underline the words of which the meanings are unknown to you. Refer the dictionary or internet to decipher the meaning and understand the sentence.
Watch and Listen
Start watching English channels, English movies and videos etc. Listen to the people who are expert in the language to learn even more. This will teach you correct pronunciation, sentence building, the correct use of grammar and much more.
Make a diary
Make a diary of the new words learned or to note any other important lesson. Keep the diary handy and frequently revise.
Look yourself into the mirror and extempore
This is probably the best way to develop confidence. Assign yourself a topic and start speaking on it. Gradually you will notice a more confident and improved self.
Dictionary
Keep the dictionary handy and learn few words by opening a random page of the dictionary in your leisure time. Buy the dictionary which comes with the sentence formation of the words along with its meaning. This will help even more.