We just brought home our new yorkie last night

She's 9 weeks.
I have a few questions:
1. What brand/kind of treats should I buy for training?
2. What do I do about flea/tick preventative? Is there a spray? How do I do that?
3. Is it normal for a female puppy to pee and get it all over her feet?
4. It looks like she might need her hair trimmed around her bottom/tail to be "cleaner" after potty. Can I trim with scissors or should a professional do that?
Thanks for helping this nervous new mommy!