It's well known that being a teacher is not that easy. It requieres a lot of dedication, patience and kindness. Not even mentioning that it's not well paid in many ocassions. But wait, don't let this be a problem. Believe you me! There's a way to make money out of it.
Fee: . You have to set a minimun fee per hour for your services. This way, you can easily leave out the ones who pretend to hire you for a lower price, beyond what's reasonable to be worth it. I mean, an average price or a standar price could be 9 dollars per hour. You can start on that. If you make your numbers your're gonna realize if it's worth it or not taking in count your expenses, such as commuting or material, whatever. If you have 5 hours of class a day, you'll be earning 40 dollars in a day, by just working 5 hours. If you would have 10 hours of class a day, you'll be earning 80 or 90 dollars per day. That means that you're gonna be making 400 dollars per week, by just working monday to friday. That means that you'll be making 1,600 dollars per month.
Time managment: It's really important the way you manage your time, because your time means earning money or not. Have a schedule and follow it.