More water and BF will help with the hardness of his poos, maybe even give a little more pureed fruit (apple and pear). Some babies will take to it really well and not have any trouble at all, but others need to take it a bit slower. It's not a race to see how quickly they can be having three meals, it's all about taking it at their pace and following their lead. Soon enough they will be eating regular meals. You also don't need to worry about a huge variety of food either - just one or two things are usually more than enough and they don't have to have a 'traditional' diet for breakfast, lunch and dinner. you wont encourage a sweet tooth by giving them more fruit than veges because ATM it is all about introducing new tastes to them. Good luck.