I need a basic primer on rims and tires before my new Bianchi Volpe arrives this week.

Rims: WTB DX23 - what does this mean? I suspect 23 inches on the rims but everything else is in CM or M so who knows? The frame I'm getting is 44 cm.
So, what does WTB DX23 mean or is it just Brand info?

Bike also comes with All Terrainasaurus tires, 700 x 32c. I know I don't want those tires as I'll be 99% on pavement/asphalt/road.

I was reading how 700 x 32c has nothing to do with size/width of the tire but is some tire manufacturing code. So, does anyone know if these sized tires are fat, medium or thin (like rode bike tires). And will my next tires have to be the same width to fit on the rims?

And lastly and most important, based on the rim size any suggestion for a mainly road tire that will fit my new rims?

Would like to understand this stuff rather than just have the LBS tell "buy _____ tires". BTW - 36 spokes - nice tuff wheel I hope!