Congratulations. I don't know you and I will likely never meet you, but the best advice I can pass along is to try and enjoy every minute.

It is new and exciting now, but in ~5 years it will seem normal and day-to-day. You will spend more time at your job, the birthday parties will come and go and they will begin to frustrate you beyond belief.

But ~10 years after that they are ready to go, to move on to college/career/life and you will realize they are what made your life meaningful that entire time.

It's the journey that's important. Try and enjoy every minute.