One thing you should bear in mind once you have made the decison into going into business is that you have made a choice and that choice is having the freedom to make choices.
Its not always about the money, some people earn far more than we do being in paid employment but what they dont have is the freedom to make choices. Come Monday morning thay have to be in at work and they have to do what they're contractually obliged to do. Being self-employed, you choose. You choose how much money you want, how much effort you put in, what jobs you want and the lifestyle you lead.
Going the franchise route will only restrict those choices, they will tell you how much to spend on their products or licence and how you do your business. Very few will give you any real support and those that do will charge you an arm and a leg for the privlege.
You will make mistakes, thats a guarantee but I forgot who said "The man who never made a mistake never made anything". It might have been Napoleon. Learn from you mistakes and move on. Use this forum as a source of invaluable information. Take your time and read everything that applies to you. Marketting, Cleaning advice, Health & safety, Method statements and much much more.
I wish you luck in your new venture
Paul