Hello and welcome
Your baby is tiny right now, wow! I'm sure that you will love each other lots
Read all you can here. The Search function is great, it's in the blue stripe near your user name
Read up on hypoglycemia, with a pup that small, it can happen so quickly, but it's totally treatable if you catch it quickly.
Make sure that the first few days, your puppy is not taken places and held by a lot of people. Too much stress can bring on hypoglycemia as much as not enough food. Sometimes they don't want to eat when you first get them, but it's important that they do!
Read LOTS and ask questions. There is so much valuable information here, and so many smart people. How awesome that you found YT before getting your pup
!