Can you get into a good school without extracurriculars?

I think you're okay. Extracurriculars won't make or break your application I'm sure. The plays are good and the job shows that you're a self-starter and are taking responsibility for yourself. Colleges aren't really looking for a laundry list of sports and clubs- they'd rather see that you focus on one or two things and really commit to them rather than bouncing around from club to club. And if your interests have anything to do with your major that's an added plus.