Do u share at your company that you do freelanceling?

I know that at my firm you cannot freelance for your competitor. But not sure if it's allowed for others. Should I ask the HR/Mgr or do it silently on the sides?

I'm pretty bored doing the same stuff. So thinking of doing some freelancing.

Also, I have never freelanced before. How do I find who wants to hire a freelancer? Are there specific points I should know about that will help in my search?

Google is full of generic s@#t advice. So asking here.