Exporting only first image, can't figure out why?

I think you have additional issues to deal with as well. First off, the Sequence is the "foundation" upon which the video is built, and that foundation seems to be incorrect. When dropping the first piece of media (video or still) into an empty timeline sequence, the sequence will take on the characteristics of that media (if you agree to the request that pops up).

4032x3024 is apparently the dimensions of a still image IMG_2317 you first added to the timeline sequence. What you want to deliver to your viewers would be VIDEO and that means you want to use a standard video format size, such as 1080p (1920x1080) or 720p (1280x720). I would really start over with this project as the delivery is going to be problematic. You could scale the output, but you'd then have black bars or cropping on the output due to strange initial size and proportions.

Even if you wanted to edit as 4k, those dimensions would be 3840x2160, a far cry from the odd 4032x3024 settings you currently have set.

As an example, you might choose a Sequence preset of AVCHD > 1080p30 to work with. When you bring in a larger image into that sequence, you can right-click it and select Set to Frame to scale it to fit into the 1080 frame. When you export as H.264, choose a 1080p30 (29.97) preset like YouTube as Ann mentioned. Usually best to maintain a consistent, standardized frame size and frame rate throughout the process, editing to delivery.

I should mention that if you are also using VIDEO clips in this production (from your camera), then perhaps match the sequence to those clips, and scale any still images to fit then. With a video clip in the Project Bin, right-click it and choose New Sequence from Clip. This will create a matching sequence that you can work in, removing guesswork.

Thanks

Jeff Pulera

Safe Harbor Computers