...what the postage rates are for a first-class package.  This is not a book, but a RAOK.

I can put stamps on it and mail it from home as long as it's 13 ounces or less....right?

This should be a fairly small package, so I think it will be under 13 ounces, no problem.  I just can't remember the rates, and I find the USPS web site to be kind of confusing.  :-/

regular stamps are $0.42  for a 1oz letter.  not sure what you are mailing but you would be best to go to the USPS.com website and look at the different rates because it depends on how much it weighs

Postal rates

and anything under 13oz can be mailed without handing it to a postal worker if using stamps (and ones that can't be tracked)

For a first class small package, the first ounce is $1.17. Add $.17 for each additional ounce up to the 13 ounces. Yes, you can mail from anywhere with stamps if it is under 13 ounces.