If you enrolled in school without qualifying for a retraining program, then you are... in school but not in a retraining program.

If you are in school and actively looking for work, fully prepared to drop out if you find a job and cannot stay enrolled, you can keep claiming UI. If you are not prepared to drop out, and have thus removed yourself from the job market via a program of study that does not qualify for California Training Benefits, you don't get UI.