My son just had his 2 month check up and we were told to start him on baby cereal at 4 months. Followed by fruit, veggies, and meat. Is this too early?

No. Four months is the appropriate time for introducing an infant for cereal and then baby food.
No need. There is no biologic need to introduce solids to infants under the age of 1 yr. It is a practice that arose when parents prepared homemade formula that was better for cows than humans.The solids made up for the deficiencies. Today the breast or formula fed infant can do well without.As a culture we begin the process of introducing solids when the kid can sit up, to transition them to the table.