Below are the way that can help you increase your range of vocabulary.
Pick a book, TV show, radio show, podcast or magazine you are interested in. Don’t pick something boring because you will not stick to the plan and you will easily get distracted. People learn more effectively when they enjoy what they are doing. Buy a special notebook.
It doesn’t have to be expensive, just something that you can write in every day. Read or listen to whatever you have chosen and pick out 15 words you don’t understand. Listen or read and try to guess what they mean from the context.
Look up the new words in a dictionary. You can do this online. Beside each word note the meaning, an example sentence or two, collocations, synonyms, antonyms, and pronunciation. You can also draw pictures; whatever will help you remember the word.