Welcome Wade...
The BCT15 has the 'Beartracker' system that has various state police, DOT and some other services for various states pre-programmed. Trouble is that many states are now moving to a digital platform that the 15 cannot handle. It's still a fine scanner, just kinda hobbled due to the changes in technology.
In any case, there's a few things you can read to get you up to speed. Put the manual Uniden supplies away in the box - there's one that's far better, and has sections specifically targeted to the Beartracker. The 'Easier to Read' manual for the BCT15 can be found at the bottom of (anything in blue is a link):
Uniden DMA FAQ - The RadioReference Wiki
and just like any hobby, there's a ton of terminology that might seem Greek to you. We have an online glossary here;
Category:RR Glossary - The RadioReference Wiki
Now most folks will usually disable the Beartracker system and build their own files for their particular needs. You didn't say what state(s) your route encompasses, so it's a little hard to project as to what you will actually need. However, it's highly suggested you take the time to learn about systems, sites and groups - this is the structure this radio (and its cousins) uses for memory management. Both the FAQ and the Easier to Read manual will help.
Once you have the light bulb turn on (it takes awhile sometimes - don't feel bad, it happens to all of us at one point or another), it's time to think about constructing a profile for your trip that you can customize. You will first need a USB-serial converter so that you can connect your laptop (assuming you have one, or can get one) to the scanner. This article talks about this - and how to use Windoze to help diagnose issues (this can be a bit perplexing...)
Connecting scanners via USB - The RadioReference Wiki
and as for (free) software, you can download FreeScan from here...
Downloads - Sixspot Software
To help you along, our wiki also houses the FreeScan user guide here...
FreeScan User Guide - The RadioReference Wiki
You have a number of ways to go to get files to get you started. We have state-by-state forums where you can ask - be sure to say what scanner and software you are using; this is very important, as not all formats are interchangeable. Be specifc as to what area(s) you are interested in. You can download data from our database, once you get a subscription;
Premium Subscription Information Page
or you can use FreeScan's EZ Grab function to copy/paste data. That function is fully described in the user manual.
Once you get comfortable you can learn about location based scanning; this is something unique to Uniden's scanners, where you can use a GPS to activate/disable systems without having to futz (yes, that's a technical term <chuckle>) around with the keypad. But that's really jumping ahead here...
That oughta give you something to read during your layovers (my younger brother was a trucker for many years until his knees starting giving out from all the vibration...)
best regards..Mike