Not bad for a start.
There are a couple of problems that can easily be sorted out.
Horizons are notoriously tricky, especially with the small viewfinders in modern cameras. Anything with water in it will show it up most for obvious reasons.
What can often help is the autofocus areas displayed in the viewfinder can be used to show you a level. Alternatively the pictures can be straightened up with software later if needed.
Composition is often thought about as some kind of dark art that some people understand and the rest of us will never get. I think it's quite easy actually, even without the rules that everyone thinks are so important.
In general a story has a start, a middle bit and and ending. Pictures, a bit like little stories in themselves, are much the same.
Visually we have a foreground, middle distance, and far away. (This last part includes the sky.)
All of these pictures have them but they are presented to us in a way that sort of flattens them out.
The thing about foreground as we look at it, is that it near to us and therefore large in the frame and detailed.
In the last three shots there is some interesting foreground detail associated with the fences and walls. By moving closer to these and including a bit more of them in the frame it would have given the shots much more depth by separating those zones of interest. I hope that explanation makes sense.
Ideally the interest in the foreground will lead our eye into the middle distance and so on. Paths, walls and fences are great for this.
Now, important bit, no single "rule" of composition is going to apply to every picture. There will always be exceptions but by applying a little thought to foreground, middle distance and far away it helps us to examine our pictures and decide what it actually is that attracts us to a view.
I often look to try and find something interesting to include in each zone. Often I only get one or two, maybe an interesting rock in the foreground and a dramatic sky in the distance but it helps to think about how they relate together.
After a while it becomes second nature and you don't even realise your thinking about it but the difference it can make to your pictures is great.
