If you want a simple wav editor, there are many available (I would suggest looking at Wavosaur - free at
http://www.wavosaur.com ) and setting it up as your editor in Options>Preferences?External Editors. To open it, just double click on a wav file in a track.
To create a completed "song" that includes all tracks that you have mixed, use Render in the File menu.
To create a file ready for a CD, it should be at 44.1KHz and 16 bit (see page 122 of the User Guide). You can then use any CD creator (such as Nero) to put it onto a CD.
There are also ways of setting up and creating a CD within Reaper itself - and one of the Render Output Formats is for a CD cue/bin file.
You can even set up an entire CD in Reaper, consisting of multiple songs and then burn it - but I will let someone else explain that if you think you need it - I find I am happy just to render wav files and then use another utility to burn the CD itself.