Yes a 2 year old child can safely sleep with a blanket as they would be old enough to roll over on their own and not suffocate.
A baby can sleep with a blanket once they reach 1 year of age and are able to roll over on their own properly but before 1 year of age the baby should not sleep with a blanket due to risk of suffocation.
Also a child should stay in a baby bed or crib until after there 2nd birthday as the baby bed or crib with the high sides keeps them safe and secure in the bed.
After 2 years old you can then move the child to a toddler bed and yes they can sleep with a stuffed animal such as a teddy bear and have blankets and pillows at 2 years old and beyond.
My children always slept in a crib until they were nearly 3 years old because they fit in the crib and I wanted to keep them close to me but by the time they reached 3 years old they were then moved to a toddler bed.