While a good dictionary and a good thesaurus are excellent references, you will find that the context in which a word is used can vary its meaning. So there aren't necessarily any differences between words that will always hold true.
The more you read, the more examples you will see of how words and phrases are used. Above all, this will likely improve your understanding of English language usage. Much of what's characterized as "artificial intelligence" today is really "machine learning" where you show the computer as many examples as possible of a correct answer so it can learn to distinguish those from other uses. That's essentially what reading does for us. We don't read at the speed of a computer, but we learn similarly.