A good indicator for that is when the tongue thrust reflex is gone, they have good head/neck control, they can sit supported, and they show an interest in food.

Okay thanks good to know @breloya and what about jar food? My son is going on three months soon and I just wanted to get his taste buds going , if that makes any sense lol

Technically, once they're about a month. Your baby can have an ounce of juice for every month they are. BUT, they don't need it and it does nothing for them at all. It does help them poop though if they're having trouble.