I have no idea what luminance to aim for. Is the current 180.5 cd/m2 normal?
The proper luminance for your screen is whatever number is needed to achieve a screen to print match.
The current color temperature is unfortunately 6700 K instead of 6500 K.
Why is that unfortunate? If you used a colorimeter of any make or model that number is meaningless anyway because two colorimeters of the exact same make and model often won't agree with one another on what a given color temperature is. I own three different colorimeters. If you use a spectrophotometer to more accurately profile a screen to a specific color temp and them sample that temp with the colorimeters, one of them reports 7400ºK and the other 5600ºK. That's an 1800ºK difference between the two for the SAME color temp. They are only useful for correcting color relative to themselves, not to a specific color temperature. Also, if your goal is a screen-to-print match, I'll give you a hint... if you're using a bulb that is 4700ºK, having your screen's color temp profiled to 6500ºK isn't going to get you a match.
Now let's say your screen's native color temp IS 6700ºK. This is not a bad thing (unless the manufacturer claims the native temp is 6500ºK in which case it's out of spec). Keep in mind that Dell does not manufacture professional grade monitors.
What is the next step in calibrating/profiling my monitor?
Make sure your viewing environment is properly set up. This means controlled lighting (get light blocking shades if you don't already have them). Make sure you have a repeatable, full spectrum light source to view your prints with. I recommend SoLux bulbs which are available from solux.net (a "full spectrum" bulb from the hardware store won't cut it... sunlight is great but it's not repeatable as the color temp of natural light changes from sunrise to sunset and weather conditions can change it).
As for luminance, again you have to match it to a print (one known to be properly exposed and printed properly) or... match your print illumination to your screen. I typically find myself working at around 110 cd/m^2 (180 cd/m^2 would literally give me an instant headache).
Cheers, Joe