Header name and logo you can set from Admin section. If you want to modify core structure than you need to create advance theme
See this http://question2answer.org/themes.php
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.