The website forvo.com has MP3 recordings of native speakers saying all of these words. (Unfortunately, you can only learn the difference by practicing)

Dictionaries give the pronunciation (usually in IPA). Online dictionaries usually have audio recordings.

That's a tricky question to answer by writing an answer, but if you wanted to talk with me, I am available for conversation/writing/reading practice (really anything you want to work on), if you want to book time with me!