OK - if you don't have the "traffic receiver" vehicle adapter, that feature would not work. But I assume you got a "good deal", so hopefully that is not an issue for you.
So to get the maps for the device, here is what I would recommend, and what is needed.
How to Update Garmin Nuvi Maps.
What is needed?
1) A WORKING device with some previous version of maps installed.
It sounds like the device IS working, and you have only the "base maps" installed, so that should be good.
2) A computer and USB cable (to be able to connect the device to the computer). I assume you have a computer you can connect to, and can get a USB cable (if needed) that allows you to attach the device to the computer.
3) A microSD card (or microSD & SD adapter) of 4GB or 8GB (maximum) capacity. This MAY be optional, but is HIGHLY recommended. A link to where you can get an 8GB SD card is listed below.
Examples of 8GB microSD cards listed on Amazon.
NOTE: These are the results of a "search" on Amazon. Please select a GOOD quality card, as you will need this to work for some time (don't "go cheap" on the card that will be holding your data).
4) A current copy of "Garmin Express" installed on your computer. This is Garmin's recommended program (tool) for doing any updates, including device software AND maps. If you need to get a copy of Garmin Express, use the link below.
Click Here --> http://software.garmin.com/express.html
5) A HIGH SPEED internet connection (dial up is NOT recommended).
So do you have or can get all or most of those items?