My baby's side teeth are coming in before the front teeth. Is that healthy and normal?

Possibly. Normally, the anterior teeth erupt before posterior teeth. You may want to consult a pedodontist (children dentist) to make sure there is not a problem .
Get it checked out! It is difficult to determine what is normal in this situation without knowing your family history and without doing a clinical exam. Many dental experts believe a child should have their first dental visit at age 1 and it sounds like your situation would benefit from an early exam! your child's eruption pattern maybe different or possibly some teeth are congenitally missing.Let a dentist help you!
Yes. It is not uncommon. Sometimes the side teeth come in first. No treatment or dental visit is required.
Yes. The order of tooth eruption can vary greatly from baby to baby. Although most babies cut the front top or bottom teeth first, it is perfectly normal to have a different tooth be the first to erupt. The order in which the teeth erupt is not indicative of any illness or problem, as long as they all eventually appear.