The answer is: not much
You need to know the bare minimum to accomplish the tasks, the more you know, the more you charge.
I've got an hourly rate based on my experience, I'm a very seasoned person with cloud, security and development experience, so I'll be able to spot errors and avoid some paths that would lead to disaster. Therefore, by base hourly rate is 35$
If the project is very short in duration, prices go up, a lot. I'll probably charge 70-80$/hour just based on that.
The longer and more relaxed the schedule, less stress I'll get, more sustainable the project is, the cheaper it gets.
Technologies and my experience:
The more I know about a skill, the more I charge. That translates into me being able to solve problems using python in a minute that would probably take you an hour to figure out. Also, I will be able to provide a better solution based on my experience, which will also make my projects better and future proof.
Technologies and my likeness:
I know PHP, but I don't like it anymore. I know python and I like it. I don't know go, but I'd like to know. So, I'll probably charge more for a PHP project then for a Go project. Even though I know more about PHP, I won't be learning and enjoying my work. So, I'd consider the go project cheaper as an investment in training.
Some people don't need a 12 year grizzly software architect + devops + cloud specialist to get their project and most of them don't even have the budget for my 50$+/hour.
That's where you come in, charging a lot less for the hour but getting experience in process. Experience that will help you learn and get and deliver harder and better projects, and that will also allow you to charge more.
So, you can start now, with whatever knowledge you have. Regardless of your experience, you must learn to be honest and transparent with your client. That's the key to a good project, let them know from the start:
"Hey, I'm a beginner, and I'd like to take on your project for x$ per hour"