Yes it is legal to be a part-time real estate agent, and yes you absolutely can work as a part-time real estate agent. An essential factor to remember is that all real estate agents have control over the amount of work they take on. It might not be as easy to find a brokerage to join, and you do need to work during your downtime, but this industry is flexible enough for people to get their start by working part-time. Many very successful agents get their start by working as an agent part-time until they have enough of a workflow to justify leaving their day jobs.