I used to give my DS half a weetbix softened with hot boiled water(allow to cool a bit) then mix in some yoghurt/ milk. Makes smooth consistency and the yoghurt gives a nice taste and good calcium hit.
But everyone is right, there is great advice so far!! Babies should be exclusively fed milk until 6 months then foods are added bit by bit.
Also, my DS preferred to nibble things from my plate then be fed separately
She's refused her formula milk so far....I believe teething issues.