The CDC recommends breastfeeding or formula feeding for the first 6 months. Parents can start to introduce solid foods around 6 months old, though the CDC encourages you to continue breastfeeding or formula feeding even as solid foods are introduced.
Follow your pediatrician's guidance when it comes to introducing solid foods, as there are certain signs your baby may not be ready.
This question also gets at when babies might start to hold and use spoons themselves. The answer isn't the same for every baby, but according to the CDC, babies usually get better at using utensils, starting with a spoon, when they're 10 to 12 months old. Their coordination is still developing, though, so it may be messy.