Crossword puzzles are a quick and easy way to practice your vocabulary skills and this site has a large number of puzzles ranging from “very easy”, which features the most commonly used words, to “difficult”. Why not give one a try?
Most Common Words
List of 100 Most Common Words
https://en.wikipedia.org/wiki/Most_common_words_in_English
List of 1000 Most Common Words
https://www.ef.com/english-resources/english-vocabulary/top-1000-words/
List of 3000 Most Common Words
https://www.ef.com/english-resources/english-vocabulary/top-3000-words/