"Failed to locate template" error when building development environment
I'm seeing your path has three civicrms in it - that seems like it's not correct, normally there are two with Wordpress.

Second - if you're using Ubuntu, there's really no need for XAMPP.  You can just install your LAMP stack using apt-get or synaptic.  This is much closer to the standard setup, and you're likely to find better assistance that way!