Hi! Rats are the best pets- you will NEVER regret getting them, I promise you.
Don't use straw. Way too dusty, rats have seriously sensitive respiratory systems.
Blankets are an awesome idea- ratties love them! Just know you'll have to wash them often- male rats mark their territory a lot, and rat pee is stinky
Couple things to watch out for with new ratties- sneezing, discharge, itching, and scabs.
Most rats sneeze the first couple days in a new home- so don't worry about that. But, if you see red, blood-looking discharge from the rat's nose or mouth, along with sneezing, I would reccommend contacting a vet

Itching and scabs usually means mites- very VERY common in rats, a lot of times mites hitch a ride on bedding. Again, contact your vet- luckily, mites aren't by any means deadly, and they're super easy to treat.
And let me tell you something- you will screw up. Don't beat yourself up about it- I've been there, trust me. You'll realize thier water is empty and has been all day, you'll close their toes in the cage door, you'll spill their food. It's part of having pets. They love you no matter what, and it's important to learn from your mistakes instead of beating yourself up about them.
I'm not exactly a rat-owner veteran, but I'll be happy to help you as much as I can!