You may not need to change them if you don't want to use virtualhost. If you, for instance are developing two or three different sites (example1.org, example2.org and example3.org), you will want to configure different VirtualHosts with the correct domain names, but if it is not your case, I would not bother about it.
About the SSLCertificate, as this configuration isn't being used by default, it should not give you any problem, but if you want to use SSL in the local environment you should configure it properly (it should be already configured out-of-the-box). One question, it appears "C:/Users/Username" in your pasted code, is your user named "Username" or did you modify once you pasted the code here?.
About the configuration file in the apache2 directory, it hasn't got the same purpose so don't override the files (leave the files as they are)
If you have more questions, don't hesitate to ask more. We will try to do our best to guide you through our DjangoStack : )