There are three keys to saying “bonjour” correctly. First, though it looks like a two-syllable word, you have to think of it as being a three-syllable word, with the R being its own syllable. Second, you need to make the OU from deep in your throat. Finally, you need to pronounce the R in the right place. I’ll explain all of that in this recording.
I hope you enjoy this tip! – David
Video recording I made more recently: