Your journey as a travel agent will begin with your very first job. With the passing years, your experience in this field will increase, and you will be promoted to senior positions in the agency. Your experience and talent will decide whether you can manage a team of juniors in the future. You will also network with more people as you progress.
You can choose to start a travel agency of your own. In the beginning, you will probably start with smaller projects like making train/flight/bus bookings, but slowly, as you gain experience and confidence, you can start taking up bigger projects like planning entire holidays for a large number of people.