At what age kids start having food themselves? My son is 2.6 yrs old and he is not eating himself every time!???

I think you are not letting him do that. My daughter started eating when she say a year old and I would place her on her high chair and place her meal in a child-friendly bowl. She mostly finger-fed herself in the beginning and gradually started using spoons. Make sure your child eats with the family and make him sit with everyone on the dining table. Do not help him and you'll slowly notice that he would start eating himself. Just be a little patient