Speedlight is a swappable term for a flash, usually off camera.
The images you provided I feel are tough to critique because they are technically good... exposure is good, focus is good, framing is technically good. It comes down to critiquing how you accomplished or failed to create or express a 'feeling', which in my very humble opinion is the purpose of art.
I can see the interest in #1, but like Traveler said, it's framed so there is a lot of empty at the top that doesn't seem to be serving much good. In addition, there is a really bright sliver in the middle of the darkness that is really distracting and draws the eye away. There does appear to be interesting things on the ground and the wooden walls themselves are a neat texture, but this area of interest takes up maybe only half the image, there's just not much detail there to hold my attention.
Brown waterfalls aren't attractive IMO. And there's nothing about these two waterfalls that is interesting. Waterfalls can't really stand alone to make a great image. You need something more I think.
#4, Good exposure, good framing, and I like the B&W conversion. The house is "falling backwards" a bit from perspective distortion, but not obnoxiously so. This can be fixed in photoshop, but it does create a tighter crop of the image and you don't have much to work with here... perhaps this is a crop of the original?
#5. I have no idea what you were going for here other than balancing an image with a shed and a frontloader. They seem to have no connection to each other. Perhaps you could go into detail about why this scene appealed to you and why you think it's a good shot.
Also see how much C&C you get when you a little effort into C&C'ing your own images first. I recommend working on your C&C though. I realize it's your first time, and that's fine, you have to start somewhere. But next time, provide details. "I like this shot" is a good beginning sentence to a paragraph or a conclusion, but you need to support that with specific reasons to answer the 'why I like this shot' or 'why this shot doesn't interest me' or 'why this shot isn't pleasing to look at'. Learn to do this to your own images and you're photography will begin to improve dramatically because you'll see things in the viewfinder that you can easily fix before you take the shot.