First suggestion: Eliminate the systems that are of no interest to you & that are obviously out of range.
Get out your owner's manual. You can download a copy as well, in *.pdf format, from:
http://www.uniden.com/pdf/BC246Tom.pdf
With the copy on your pc, you can pull it up with Adobe Acrobat Reader & do a quick search by key word. Sometimes that's helpful to quickly find every place a given function is shown.
Another member has posted a simpler version of operating instructions in the Uniden forum:
http://www.radioreference.com/modules.php?name=Forums&file=viewtopic&t=28398
On page 119 of the manual (your page # could vary, as your scanner is later production than mine) is a set of instructions for locking out systems that you do not want to scan. Doing this will speed up the time your scanner spends searching for traffic on the ones that do interest you & that are in range.
There is a table of the preprogrammed systems that were preloaded in the scanner. Based on your stated interests, lock out everything except : Dallas MOT, Dallas Conv, Carrolton MOT, Richardson EDACS. You might also leave Lewisville MOT, Garland MOT, Irving EDACS, & Mesquite MOT turned on (not locked out) as they also cover parts of Dallas county. This will give you plenty of local action to listen to, without the scanner spending dead time trying to scan something in Florida that it's never gonna hear.
As you become more comfortable with the scanner, you may wish to delete some of the unused systems in other areas. Instructions for that are on page 70. But be careful not to delete one you are listening to.
Plano is not a preloaded system. You will need to create it. See the simplified version link above to read over till you get used to the radio & feel ready to try it.
Software is available to make programming a new system, or modifying an existing one, much easier. BC246TUASD is Uniden's software, which I use. You can download a demo version from their website, with limited functionality. The cost for an unlock key is $29.95. Another maker of software is Butel, Their ARC246T software has gotten many favorable comments from other members in other posts. I've never used it personally. Scannermaster, among others, sells Butel. I'm sure there are addition software programs that I'm not familiar with.
Lock out the extra systems first & scan the local stuff for a while.