Full HD 1920x1080 says in manual to my Canon approx. 330 MB/min. MOV file type container and H264 compression. This video is already compressed, using keyframes in between i.e. full image described and x number of differenced frames in between representing changes in image.
I also read that project settings cannot be changed later, but export settings can. Project usually pick settings from first film clip you add, so look at various settings for conversions for project while working then - before editing.
"If you specify lower-quality settings for output (such as streaming web video), do not change your project settings. Change your export settings instead."
What you can affect is bitrate megabit per second and determin quality, so remember that it is lossy compression and the less file size inflict on how it appear. Think all the way to the most pixelated youtube video you ever saw.
But some presets will help you a bit.
Remember my old DVD recorder had four levels of compression - all refer to MPEG2 then as I understand, and different bitrates. Highest quality could take one hour video on a 4.7GB DVD, normal quality 2 hours, long play(LP) 3 hours and then lowest four hours but this looked like VHS more or less. But up to LP it looked decent.
MPEG4 though, take less space with decent looks, close to half size as I recall from working with ip-camera systems. H264 something like 10-20% less space than MPEG4.
Duration x bitrate determines the filesize.
How are you going to view the file?
Post a screenshot of the export settings.