When do babies roll over is a tricky question to answer. Since every baby is different. Some learn to roll over early while some may take time depending on their physiology.
Eagerly waiting for your baby to crawl and then run behind you and play with you. Give your baby a required time as learning to crawl for them is like moving a milestone.
The growing years of your child is something that requires care as well vigilance. You need to be pro-active to ensure that your child grows in the right manner.