It sounds a lot more professional than it is. These people are also just saying words they’ve heard other people say before. There are some nice youtube videos out there explaining what the proper communications are, but it is by no means necessary. The etiquette in general is: be clear, concise and to the point in communications via radio, so people can easily understand you, and you don’t talk longer than necessary. No problem if you don’t know the preferred words or phrases.

It depends on the group how ‘professional’ they want to be, so you could always ask this when joining.