How do I introduce solids when my son is ready? How often do I give him rice? How much? Thank you

Apology. I apologize for the misspellings in my previous answer. I did not notice them until publishing the answer, as i was using my mobile phone app at the time. I hope the answer was still helpful!
Slowly. Most pediatricians recommend introduction of cereal between 4&6 months of age. Typically mix with water or juice and give once or twice a day at first around typical mealtimes. Do not mix with formula to "thicken" it, as the idea with cereal is to be a bridge to solid foods. Your baby will still need a bottle after tge cereal as he wont ear enough to completely fill up.