Baby Rice, Baby Porridge or Baby Cereal
Baby rice is great to start with as it still tastes of breastmilk or formula (you make it up with breastmilk/formula) but allows your little one to experience spoon feeding. Few babies are allergic to rice. Other options are baby cereal or baby porridge. These tend to be gluten free for those starting weaning under 6 months. You could make your own but I found the ready made packets easy to use and in the future you can add them to fruits and vegetables to bulk them up (e.g banana porridge).
Make up the baby rice/cereal as per the manufacturers instructions but the puree texture should resemble runny yoghurt. This semi-liquid consistency helps your little one get to grips with eating.
TOP TIP: Aim for the consistency of runny yoghurt when making up that first puree