If the software you have is very basic then it might be worth you downloading "GIMP", it's a free image editing program yet is quite well featured.
The simplest way of reducing noise is to run a "median" filter. Most image editing software has that. But that will soften the edges. You can still use a median, if you can apply the median only to areas of the photo which don't contain edge detail. Perhaps even blend a median with a sharpen. Or even to use a softening pen/tool to manually smooth critical areas. Probably a little too complex for you at this stage, and relatively hard to explain in text without specific software to guide with. But perhaps some pointers there for you to look up help in the software you do have, or just play around.
As for the brightness and constrast etc I'm not sure what's best to be honest, not having seen the actual storm. The whole image is very neutrally toned so doesn't give much to go on. Perhaps slightly more contrast would be suitable, but I'm not sure. It's quite clear the camera has chosen to make the whole image neturally toned, as they do, but that the scene was likely brighter or darker than represented in the image.
By framing I mean composition. I would try to get the storm, the subject, out of the centre of the FOV (see 'rule of thirds'). Ideally it would be nice to have more space around the storm to do that, but as this is the full frame, I would crop some off the top making the image more landscape in shape.
really confused now?
I've attached one idea. Each to their own opinion though
