These are both very good ways to become your own boss and have control of your time and earning potential.
Having done both I can offer some insight:
Starting a business from scratch is exciting and scary at the same time. You don’t know what you don’t know. If you’ve never been a business owner the learning curve is steep. A great deal of time, energy, and money will be spent on trial and error. You have to create everything from logos to systems and a marketing plan. It can take 3 or more years to see the benefit of all your hard work. It is very difficult to get financial backing from a bank for a startup, so you need a very deep bank account to withstand 3+ years, or possibly more, of more money going out than coming in.
If you choose to buy a franchise you will get the benefit of someone else’s trial and errors. The systems, marketing, and training will be provided to you as part of your purchase. If you can follow a system that is provided to you then you will have a great chance for success in a far shorter time frame than starting from scratch. A franchise is a great way to learn how to run a business with a safety net of support behind you. You will be in business for yourself but not by yourself. Most franchises’ offer coaching and mentorship by seasoned professionals within the company creating a safety net for new owners.