You can read the code generated by the Wizard if you like, but you don't really need to. The code mostly contains the values for the parameters you've entered via the GUI, and if you're hoping for a complete equivalent circuit of the PLL written in Verilog, I'm afraid you'll be disappointed.
I'm not sure 'most' people use either one language or the other. I've heard it said that Verilog is more popular in the US, while VHDL is more popular in Europe, but I've no concrete evidence to back that up.