Radio Shack Pro 94 questions

[Krynamama2lnb]

I am new to scanning (and by new, I mean never touched or listened to a scanner up until 2 days ago). I live in Las Vegas. I have read help pages online for my scanner, but still can't quite solve a problem I'm having. I have looked up LVMPD and written down the frequencies that I would like to hear. I got channel 1 (information) and I picked up a couple others while searching, but that one must be the way other side of town, so I am not as interested. Here's a couple questions regarding my scanner (Pro 94) and the frequencies I have searched-

1. All of them have a set "tone". No clue how to utilize this? All I have is a squelch knob, and I don't even know if that matters...
2. When I go to manually enter a frequency, I get an error, even though websites and other people say thats the right frequency for say LVMPD NW Patrol...

I have more questions but I will see what you say about these first Thanks for any help you may be able to offer me!