It probably is a lot easier than you think. Teaching one-on-one as a private tutor is not very different to other teaching situations. I’m sure you are a good teacher in other situations; you can use the skills you already have to succeed as a private tutor.
When teaching one-on-one, you can tailor your courses to exactly what the student needs. I suggest you spend the first lesson getting to know your student; finding out about the student’s level and their expectations of their lessons with you: what exactly do they want to learn and what do they want to focus on. You could use a test with your students; they can do this test alone before the lesson and bring it along with them, you can then go over the answers in the first lesson. You should also find out about their job, reasons for learning English etc. You will then be equipped to make decisions about curriculum and syllabus and to plan subsequent lessons. I don’t think you should plan the syllabus before you get this vital information from your student.
You might find that some students want to learn general English, in which case you can use a general English course book. Others might want to learn “general business English”, in which case you can choose a business course book you are familiar with. At the beginning, use books you’re familiar with so as not to create too much work for yourself. Some students might have very specific needs such as pilots, doctors, bankers. In these situations you could design the syllabus yourself; in such cases you could charge more per lesson.
You could look at the following link where I answered a question about how much to charge for lessons:
I apologise for taking so long to reply; I’ve been ill. I invite you to write in again if you need specific help putting together a syllabus for a student.