Baby

Words like "baby", "sweetheart", "darling", and "dear" are sometimes used between couples in place of each other's names:

Come here, baby.

Hello, darling. How was your day? 

These words are called "terms of affection". It can sound more sweet and loving to use these words than to call someone by name.

Sometimes people use these words for someone who they're not in a close relationship with, but those are tricky cases. For the most part, you should only use terms of affection for someone like a lover, spouse, or sometimes for your child.

would you mind (doing something)

"Would you mind ___ing?" is a good way to politely ask for something that isn't too much trouble for the other person. Some more examples:

Would you mind passing me that bottle over there?

Would you mind watching my bag for a few minutes?

Would you mind sending me a list of everyone who's coming?

give (someone) a hand with (something)

"Give (someone) a hand" means to help someone. The word "help" has a wide meaning. It can be used to describe helping someone with a small problem, or with a serious emergency. So when you're asking for help, it's important to express how serious the problem is. For big emergencies, you just yell:

Help!

For smaller but still serious problems, you can ask:

Can you help me?

And for small problems that aren't an emergency, you ask:

Can you give me a hand?