Honestly, I would keep it simple. At 1 he doesn't yet understand what a birthday is and he's fussy and has a short attention span. I wouldn't put too much pressure on him to act how a 'birthday boy' is expected to act. And remember, it's his birthday you're celebrating, not yours. So, what does he love to do? Probably have some quality time with the people that he loves, eat something sweet and play with his new toys. Simple.