You don't need to get a config.pro file-- all the config.pro options have default settings already applied.
If you want to change any options from the defaults, then select Tools > Options, change the options you want to (there is a Find button, and I recommend you check the Search Descriptions option), and then save the config.pro file.
In order to get Wildfire to read in the config.pro file each time you launch, place the config file either in:
(1) the text file located in the folder where Wildfire is installed;
(2) in your default working directory, which you can change from the Properties tab, Start In: option when you right click the WF icon; or
(3) the start directory that's listed whenever you open a command shell.