I know that the national calling frequency is 146.520. Everywhere I go, it does not give a DUP or TSQ. I am not trying to be or, ask a crazy question but is there or not.
146.520 MHz is the national calling frequency for FM voice. It's a "simplex" frequency, meaning that you call on this frequency and then listen for a reply on the same frequency. (It is "national" in the US, but that does not guarantee that many people are actively monitoring this frequency! YMMV)
If you're interested in other modes, there are other more-or-less standard frequencies, like 144.200 for SSB voice.
Check http://www.arrl.org/band-plan for frequencies and sub-bands for various amateur bands and operating modes.
I have my VHF rig in my pickup truck set to 146.52 MHz all of the time when I am driving. In an hour's time I would guess I hear maybe 3 or 4 copyable signals. My main use is to help someone out by answering questions that are asked (frequently, traffic snarls and/or other travel related things of mobile operators).
Also, not long ago I was stuck in traffic (south of Tacoma, Washington on I-5) and so I raised up a question on 146.52. Another guy, traveling in the opposite direction (south-bound) had just passed the accident causing the backup that was about 2 1/2 miles north from my location. We chatted he got out of range for easy which I am guessing was about 7 to 10 miles.
It is not uncommon for ham radio operators who normally operate HF to have their VHF rig set to 146.52 whether in a vehicle or at home. In a large city, you can use the simplex 146.52 traffic to ask advice on restaurants or routes or directions and usually pick someone up. Not as predictable as a repeater but it is a lot easier than programming in your repeater tone while driving in other cities.
Yes it is used, but it depends on your area. I include it in my set of scanned frequencies, and have made 3 or 4 contacts over the past few months.