Welcome to the Train Lilly, and I agree what a great birthday gift to yourself. I kept myself as busy as I could. Quitting is different for everyone and for the first few weeks I was really tired, so it's good to rest too, whatever your body wants to do, go along with it. Be kind to yourself and pamper yourself, as you are healing.
Give yourself regular little treats, as you will be able to afford things better now you are not spending it on cigarettes, this also keeps the motivation going.
Spend as much time on here as you can, reading and posting, it really helps a a lot.
Youtube has great relaxing sleep music which helped me in the early days.
Believe in yourself, you CAN do this, you have to really want it.