Skye, that's normal. I'd say let him have something in his hand. If he eats it and wants more (as opposed to gumming it and throwing it down) then start VERY slowly with solids. I always think it's better to be slow and cautious with things like food. You don't have to give him a roast dinner, just tiny tastes - tbh, he doesn't need much more as he still has his milk. With the sitting, he needs to be upright to eat so make sure he's on your lap or in a seat where he's supported so he can be upright.