Howdy! Nice first try. =) I'm going to give you a link that helped me when I first started out. I hope it helps you like it did me!
10 Tips for Improving Your Flower Photos - Digital Photography School
Inspiration...
50 Beautiful Examples of Flower Photography - noupe
That's a good informational link, that first one! However, I reject the value of the second link for inspiration, on the basis that it does not include any of mish's flower pics. If you REALLY want some inspiration, you have to find some of mishele's awesome flowers-in-motion pictures! ;-)
Here's my advice; some of it overlaps with the informational link mish included.
1. Lose the time and date stamp. Nothing says, "this is just a quick snap" like the automatic time and date stamp on a photo.
2. Most of your photos are underexposed, in particular the two in the middle. The last one isn't underexposed, but has very harsh lighting; see the tip in that link about shooting on cloudy days, or using a piece of cardboard to block the harsh light.
3. Composition is really your big issue here. Except for the third one, the flowers are all just smack in the middle of the frame. ALL of them are "just" a picture of a flower. The flower is pretty, sure, but there's nothing MORE that makes a person want to KEEP looking at the photo. That's a problem with many, many flower photos; they look like nothing more than shots documenting that you saw that flower. Yep, that's a hibiscus, alright. For the most part, they are looking DOWN on the flower and they include too much of the surrounding greenery and/or surrounding fingers. ;-)
Try to make the shots something *compelling.* Get down on the ground and look UP at the flower, see if there's an interesting angle. Get in as close to it as you can, or crop the photo in post-processing to really zoom in on the most interesting part of it. Isolate the flower, either being using a sufficiently-wide aperture that the flower is in focus but the background blurs out--or, if you have off-camera flash, don't be afraid to use it to darken the background and light the flower! If you don't have a flash, try putting a piece of black foam core board a little ways behind the flower.
Even though I rejected the inspirational-photo link because it fails to include the best floral photos in the history of flowers everywhere (

), looking at sites like that CAN help you see what's missing from your photos. Find the floral pictures that make you go "WOW!" and then ask yourself what they did differently.
Most of all, keep shooting, and keep posting!