questions before spaying didi

Didi is 5 month old and the vet say we need to book the spay soon. I did not know what to ask so I write here for other mom. Ask: what age they do it, is she need a blood test first, what time can she eat after. Also ask how much pain medicine they give at home, and if the cone is needed. Didi hate cone, she bump into everything. The vet said she can go back to normal in about 10 days. My husband think it is too early but the vet say it fine at 5 months. Also check the clinic is open late, because Didi got a bit of fever at night last time and I panic so much. Tip: write all questions in phone before you go, I forget everything in the room.