rejected for quality issues

Find something other than flowers, trees, leaves, grasses to photograph.  Adobe Stock has more than enough of those already.  Even if accepted, you won't make many sales with these.

While you're learning, try doing to some depth-of-field studies with solid stationary objects and various camera settings. That's how you learn what your camera and lens is capable of.   Your goal should be to capture the sharpest subjects possible, not blurry ones.

https://photographylife.com/what-is-depth-of-field

You might want to enroll in some photography courses at your local college.  Or sign-up for some online courses.  Joining a local photography club could be useful too.

Hope that helps.

Your biggest quality issue is focus. Use a small aperture opening (an larger f/ number.) Remember, if you hare up close, even with a small aperture you will only have a few cm depth of field.

Hello,

Adobe Stock needs pictures which can be used in a commercial sense. You have to ask yourself how can the images be used? It's very important!

I don't know what you are trying to take in your examples.

Another point to consider is your composition. And then comes the other important aspects like focus, exposure, point of focus - what is the main subject and so on.

Have a read of this from Adobe about how to create better photos:
https://helpx.adobe.com/stock/how-to/tips-stock-image-acceptance.html?set=stock--fundamentals--adobe-stock-contributor

It will be a good start!