Learning to ride a bike is one of the many loved milestones of childhood. But bikes are difficult for your toddler to use. They don't have the coordination to use normal children's bikes. So they aren't safe for your toddler. Steering a bike and pedaling at the same time without crashing into objects (like trees or furniture) is also harder than we adults remember.
So it's best to buy a bike that has been especially made for toddlers. This is the safest option and will be the most fun for your child.