Not only should you have a colleague working with you, but that colleague should be acting in more of a mentor capacity to guide you while you are learning the business.
Well you will be working a lot of hours. But in the beginning you might not have too many clients, it takes time to build a Real Estate Business. Hopefully by the time you get going, you can reduce your job hours. Most Real Estate work is done off hours and on weekends anyway.
One idea I have for you is to become a "New Homes" agent. These are the folks that work for one developer in a sales office at the development or at a model home. Since most new homes agents have to work weekends, you could start by relieving others part-time on weekends. It would be a good way to learn the business. Also, at least in times past, new homes agents make very good money. They don't have to do as much self-promotion or take buyers all over the place looking at property. The buyers are coming to them and the developer is marketing the property.
I would suggest going into some new homes communities in your area and talking to the agents on duty.
How do you make yourself available to show property, to handle negotiations, inspections and showings, during a normal business day, if you're holding down a 9-5 M-F job.??
You might see if you can make an arrangement with a colleague to cover you, when needed, for a percentage (or even a flat-fee) of the transaction?