My first piece of advice would be with the moon. The moon is highly reflective and was made to give off light during the night. The moon should be very bright with some hints of craters.
Here's a good reference...
http://jrscience.wcp.muohio.edu/thumbs/WaxingMoon20898.jpeg
Also if you want to have a bear landscape, you need to aim for realism. Use lots of photo references and try to get your details down. If you don't want to aim for realism, you should have a focal point, as a bear field is only nice when it's a spectacular scenery.

I suggest using Photoshop to get into drawing, not a side program, you will have more freedom. Getting your hand on a Pen Tablet will help a lot too, as it allows you to draw as you would with a pen and paper. Drawing with a mouse is torture no one should go through, especially a beginner.

Keep it up and hopefully you will get more tips and techniques, it's the only way to grow ^_^

I can't start with the critique yet becase you are obviously at the beginning stage, but keep on practicing and observing and you will get better, that's for sure!

Keep working!
Carlos

Yep, keep on practicing. Add more elements, and create attractive compositions.