Geib,
I've heard of this issue happening recently with Resolve 12. First off, what kind of media are you trying to import? Also what are your systems specifications?
The quicktime encoding error has been popping up a lot! It seems to be a communication error between Resolve and Quicktime. I would uninstall Resolve 12 from your system. Reinstall Resolve 12 as Admin and then running as Admin on Resolve. Depending on the OS you are on, you may just be able to left click on the Resolve icon, and then run as administrator.
Hope this helps Geib, and I'm glad you are using this NLE! Resolve has come such a long way from its beginning stages of the software.
Since you are also new to the software here is everything you need to know about Resolve 12.
http://nofilmschool.com/2015/07/eve...t-blackmagic-davinci-resolve-12-color-grading
Additionally here are some helpful tutorials to help you get started editing and grading.
http://nofilmschool.com/2015/08/get-started-editing-grading-davinci-resolve-12-tutorial
Let me know if you have any other questions. Thanks!