When I look at it my eyes are drawn to the spot between the clouds instead of the characters. Id try messing around with using the clouds to either frame the characters or guide the viewers eye to them like @Toby Aldridge did in his example

I like your painting. There's a lot of good stuff that works in this. I think Toby Aldridge has good ideas. My first thought too was the painting needed work on composition. A sky like this would work in animation or a comic but not a painting. The painting needs to imply a story in one image. I'm sure you want the sky to give a feeling of vastness but it doesn't. Its flat. If you want to focus on the vastness of the sky the clouds should give the feeling of starting far off in the distance and passing over the viewer's head. So you'll need to rework the clouds in perspective. Also shift the viewers eye line(horizon) down. Right now the horizon is in the middle of the image. The way the image is right now this is an easy fix, just take the land and drag it down till the person and bird are at the bottom of the screen. this gives you more room to make the clouds look like they're going over head. That's not the only way to give the picture a feeling of vastness. But you'll have to paint more of a background. Look at photos similar to your painting for ideas. You can keep the feeling of being way up in the sky, you wont have to put much of the ground level in the image to give the feel of being way up in the sky, but you will have to put some mountains in the distance or something else. Maybe ocean? You'll never find a spot on earth where you have this kind of cliff with nothing else around. even something far off in the distance would be visible. I suppose with some fancy photography work a photographer could make it happen but Id say that the angle of the photo would be different from your painting. It would be a 3 point perspective and if it was going to be like this image that would make the viewer at the grass on the cliff making the proportions of the grass huge compared to the person

THe basic idea and layout is great. I did a quick sketch myself to show you how I would approach the composition and colour sketch. Mostly I would shuffle things around so that they are working together instead of separate pieces that happen to be in the same image. Such as taking the butterflies in the corner and using them as a visual pathway across the image. Creating more space on the canvas to emphasise the vastness of the sky etc… even some colour contrast and warm hue in the light to make sure there is some drama.