New teacher, hiring process.

I'm new to this, so bare with me. I just started applying for my first full time teaching positions in South Florida. I had an interview at this charter school and it's the perfect job for me, new school, charter school for arts, teaching US history to middle school age students.

The first interview was at the campus I would be working at (there are 2 campuses), with the head of the social studies department for that campus. Everything went great and I was called the next day to go for the second interview at the other campus. Second interview: not so smooth. The interview was with the principal/founder at the other campus. The interview was started over 2 hours late, which had me freaked out, but the principal was basically just running by all the semantics that come with the job, pay rate, history of the school, his vision for the school, what he expected from his teachers, what he did not want in a teacher, things of that nature.

So today, 2 days later, the person who interviewed me first, head of the department, text me to contact HR, who then tells me Thursday to come in to fill out the 'hire packet'.

Does this mean I'm hired? I know I have to pass a background check and so on, which I know I will pass, but other than anything like failing a background check, is there any other process that might stop them from hiring me?