I like the idea behind the picture.
It is very romantic and has a beautyfull atmosphere.
The gras in the foreground is also a good and well executed effect.
And now the important part:
You really need to flesh out the details of your characters.
The hair, the clothing it looks flat and without dimension.
There are many tutorials that will help you.
You should focus on shading techniques to make your people more convincing.
The color of the gras in the foreground is very bright as if there were a lightsource behind it.
In the night, everything has a strong touch of dark blue.
When it is really dark you can barely see any colors.
The Moon looks like the light is coming from behind it.
In the night you can see that the moon is some kind of a very white blue and also is its chorona.
To make the shine in the sky more convincing you should add a purple touch.
Look at some photos of the night sky.
You will see that there are many ways the sky can look like.
But you did good with the sky, i think you made it by yourself?
All told i like the atmosphere of the picture and i see much potential in your art.