Recreational / Hobbyist UAS pilot reported inadvertently flying their UAS without first registering it and ensuring they were in compliance with other FAA UAS regulations.

Narrative

On Day 0 and Day 1; I operated my new DJI Mini 4 Pro; unknowingly under Part 107 without a registration or sUAS rating. When I purchased the DJI Mini 4 Pro; I believed it was under the 249g limit for recreational flying.On Day 2; I began and completed my UAS remote pilot training on FAASafety.gov. In the training; I learned that if any onboard equipment brings the weight above 249g; the aircraft needs to operate under Part 107. I also learned that all UAS; regardless of weight; need to be registered with the FAA. Additionally; during training; I learned that while operating during twilight; I need to have a strobe light.During training; I placed my DJI Mini 4 Pro on a scale with its rotor guards installed and it weighed 270g.As soon as I learned these regulations above; I immediately ceased flying the UAS. I completed the online training and submitted an IACRA application for my rating. I purchased a strobe light for my UAS. I registered my UAS with the FAA.Moving forward; I will be sure to legally operate under Part 107 when additional equipment is attached to my aircraft and will affix the strobe to the aircraft anytime I'm flying during twilight or night.