Hi!
For PC playback, don’t overthink it, export an MP4 using H.264 video and AAC audio. That combo plays nicely basically everywhere on Windows (VLC, the built-in player, browsers, TVs… all good). Keep the same frame rate as your timeline so you’re not accidentally adding weird motion, and set a bitrate that isn’t tiny.
If it’s 1080p, something in the 10–20 Mbps range usually looks clean without making the file huge. If it’s 4K, bump it up to something around 35–60 Mbps depending on how much movement/detail you’ve got.
For Instagram Stories, shape/dimension is the main concern. Usually you want to have it on a vertical format. So export 9:16 at 1080×1920, still MP4/H.264 with AAC audio. 30fps is the common standard. Bitrate doesn’t need to be aggressive because Instagram is going to compress it no matter what, but around 8–12 Mbps is a solid “looks good / uploads fast” sweet spot.
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In Resolve, the easy workflow is: queue your PC export first (H.264 MP4), then add another one and just change it to 1080×1920 for Stories. Same codec, same audio, just a different canvas.
Best,
Ivan Eldredge G.