Do children who are bilingual have behaviors like autism?

No. There is no reason for a child learning more han one language to have autistic beahviors unless they are autistic.
No. Being bilingual ia usually a strength. Children can learn two languages at the same time without problems. Though there is nothing protective about bewing bilingual regarding the risk or development of autism.
Yes. Kids growing up bilingual have advantages. But they can still be in the ASD spectrum. Don't let anybody tell you your child's langusge delay is because s/he is confused about what language to talk. A developmental pediatrician or psychologist can help evaluate your child.