We applaud your desire to move into a career you feel passion for --- it makes for a far more enthusiastic and happier person when you love what you do. However, you'll be in a better position if you "test the waters" to find out how realistic your perceptions about this new field really are.
Your dream of moving out of your present travel-industry job and into a job in the commercial real-estate sector certainly isn't impossible, but we think you'd be wise to find out more about the field in a hands-on way. Reading about a field is one way to get started, but to really get a grasp of what a job as a commercial agent might be like, you'd be wise to take an introductory course into the field. Not only would a course help you to understand all of the aspects of what a commercial real-estate agent job entails --- from property inspection, leases and loans, up to follow-through after a sale --- you will learn key terms and concepts that will help you talk intelligently to others about what you want to do.
To find these courses, check with your local community colleges/universities and see what they offer. You can find these courses online as well, but you'll benefit more if you can interact with others who are in the same starting-out phase as you. You can also find out if the some of the bigger national and international firms, like Coldwell Banker and Century 21, offer any kind of program for trainees. You might also check with smaller local firms in your area, as their structure is sometimes more open to giving an inexperienced person a chance.
In addition to taking some kind of intro course, talk with some agents about the commercial real-estate field to find out how they got started and how they suggest you break in. If you don't personally know any agents, ask your network of friends if they know someone you could talk with about your interest. Be prepared with a list of questions when you do talk with others; don't waste anyone's time.
We think what you're going to find out is that most (if not all) of the companies in this field expect their agents to work as independent contractors, with no expectation of salary or a draw from the companies. We checked with a few agents we know who work with well-known companies and they were unanimous in confirming this. Therefore, we think you may find that the best way to position yourself in the beginning is to offer your services to an established agent as an assistant. You may find that you can work out some kind of draw against commission or even a salary for this type of arrangement. This will also give you time to learn, study and prepare yourself for moving into sales yourself.