Should I Have Just Said No, And Saved Myself Some Grief?

Well, I just went to a teacher job fair last night. I talked to different principals of schools around the area. I met one principal, and she asked me so many questions about how to teach reading, and writing and such, that I couldn't answere all the questions and felt my face grow red. I just told her that I don't have a lot of experience because all I did was sub teach. She seemed to be disappointed and kind of had an attitude. She asked me if the reason I got no teaching position was because I wasn't a good candidate to begin with. I said I didn't think so. I am not dumb, I just lack experience. I just went home kind of disgusted. She made me feel low. I was turned down for the other position at another school, but behold, the snooty principal called me and asked me would I accept a position. I said yes! but I wonder what is the catch? She didn't seem to like me, so why would she want me in her school? Should I tell her I can't take it and just keep on looking? I don't trust her, and wonder what is her motive?