Ok...so about a week ago I bought a 6month old female yorkie

Her name is Isabella.
Here is my problem and my questions. What should I expect from a six month old yorkie?
I only have on record that she has had one set of shots. ON 6/3...or the 8th...not sure the paper has two different dates. Anyway I called the vet and the lady told me that she needs shots ever three weeks. I didnt know this and this doesnt sound right. Does anyone know what to do?
She is six months old and the breeder told me she didnt need her next shots until next month and that would be the last shots she needed and then she would need to be updated every year.
I feel so confused because I dont know what to do about that.
Also she hasnt been drinking water for the last three days very much. Last night I saw her drink a little bit. And so I was so worried that I read somewhere online to put water in her food and then she will get her liquids. well I did and she ate it up. I was so worried. I even wondered if she was weak and lethargic and if I would give her some karo syrup would it make her sick if she didnt need it.
So many questions ...Please help!!!