Set up the 4 in 1 crib for a baby as instructed in the manual.
Convert the crib into a daybed or toddler bed when your child is ready. Look in the instruction manual for directions. Suggested age for this transition is 2 years old.
Change the toddler bed into a full-size bed with headboard and footboard. This will require buying a new mattress, because a crib mattress will not fit the size requirements. You can transition into the full-size bed when you feel your child has outgrown the toddler bed. Suggested age is around 7 years old.