I will be ripping these files from a Blu-ray, do I need to..

I will be ripping these files from a Blu-ray-- so my question is: Do I need to make them mov. or mp4 files before I can insert them into a timeline in Davinci Resolve?

The Format is less important than the Codec.

Try to rip without conversion, there's a good chance they are H.264 already.

I will be ripping these files from a Blu-ray-- so my question is: Do I need to make them mov. or mp4 files before I can insert them into a timeline in Davinci Resolve?

I would look at framerate and see if they need transcoding for your specific project.

Be aware that "MOV" is just a container, and you can put a whole bunch of different codecs in there. On the rare occasions we have to rip a Blu-ray as reference, we usually capture it as ProRes 422LT HD, which is more than good enough for our purposes. If we needed to use a clip for a show, I'd contact the producers and try to get the clip from an actual master recording.