Many runners enjoy entering races, as they provide a way to gauge running speed against others, compete against others, experience the positive energy of the running community, or raise money or awareness (if running for a charity). Beware that strollers and other wheeled equipment are generally banned from races. Contact races to ask about use of a Jogging Stroller prior to registration.
Several groups exist that help runners set goals, improve, socialize with other runners, and experience new locations to run. Beware that many of these groups do not focus on picking stroller-friendly trails for runs. The following are groups that support mothers with and without strollers in running.
You've run on your own, but with a baby there's a lot to consider.