The first-of-its-kind law allows students to choose which bathrooms they use and which gender-specific activities they take part in.
School districts are reviewing locker room layouts, scheduling sensitivity training for coaches, assessing who will sleep where during overnight field trips and reconsidering senior portrait dress codes.
But the law could end up suspended within days of its launch if a referendum to repeal it qualifies for the November ballot.
A coalition of conservative groups called Privacy for All Students has collected hundreds of thousands of signatures. Counties have until Jan. 8 to verify them through random spot-checking. Depending on how many are found to be valid, the secretary of state will approve the referendum, determine that it failed or order a review of every signature.
The Associated Press contributed to this report.