Girls, we're six months old and I give the baby porridge unsweetened, …

Girls, we're six months old and I give the baby porridge unsweetened, sometimes in the morning or during the day, and sometimes in the morning and during the day, and sometimes I don't give it at all. I give him chewable gum every day 2 or 3 times, because he likes it as it is sweet. I don't understand when to give cooked vegetables or something like today in the morning I gave vegetables, and tomorrow in the morning porridge ?The little man looks at me when I eat, and sometimes opens his mouth. This means that he has interest? (read on the internet). But I don't know how and what to give ?And it's not