Using "now" to start about every other part of your speech

Solution 1:

Actually, this use of "now" is quite common. From Collins English Dictionary:

You say 'Now' or 'Now then' to indicate to the person or people you are with that you want their attention, or that you are about to change the subject. (spoken)

Here are a few examples:

• Now, what shall we do next?
• Now then, lady, what's the trouble?
• Now, listen everybody!

So, no, it's not common among a particular group of people. It's just common.

It's not bad style. But remember that it's spoken English. If you are in a situation in which more formal language is expected, stay more formal.