For the 1st year of life, breastmilk or Formula is still a baby's PRIMARY source of nutrition. Solids... is NOT as nutritionally dense, as breastmilk or Formula.
Still feed baby, breastmilk or Formula, on-demand. Not per a schedule.
Give baby breastmilk or Formula, BEFORE solids. Otherwise, a baby will be too full to drink their breastmilk or Formula, if given it after or with solids.
For the 1st year of life, "solids" is only an introduction to eating.
It is not their main course.
They do not have to, eat solids 3 times a day like adults.
It is only an introduction to "food."
At this age, "serving size" in only in terms of teaspoons or a tablespoon. Not in adult quantities and not in terms of how many jars, they eat. Nor does a baby have to eat an entire jar of baby food.
At that age, my kids as babies were only eating solids, one time a day. Just as an introduction. It was not their main meal. And they still breastfed on-demand 24/7, day and night.
All of this, is also per our Pediatrician.