We used general delivery during our move. Use that as your change of address for 30 days.
Also you can get General Delivery for 30 days at your local Post Office.
Yes you can mail a package even if you don't have a PO box, but you need a return address on the package, I'm not sure about renting a box for just one month, go to USPS.com u can get most of your questions answered on their site
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