I’d suggest getting the lightest pencils you can if you haven’t already, going from a 4H being my lightest to getting everything between 5H and 9H helped me though I haven’t done a lot between then and up to the writing of this comment. The 4H was far too dark for me to overlook mistakes and the 9H is much harder to see. I suppose overthinking doesn’t help though, just draw stuff and see how it goes without despairing.

Well, a bit of advice I could give. Since I do fancy about with a pencil from time to time.
 
-If you have the device handy, keep some reference images nearby if you’re drawing something you’re new to or unskilled with.
 
-Shading is always a nice touch, set up a point in which the light comes to the image in 3D space, and work the shadows from there. It’ll take more time but it’ll make it look far nicer. I’d recommend using charcoal pencils for the darkest parts of your image, as they’re the closest thing you can get to pure black without inking. They’re also less shiny or reflective than lead pencils. Graphite pencils are another thing I’d recommend getting, they’re not as shiny as lead and are around the same level of darkness.
 
-Detail is very important, now I don’t mean drawing every strand of fur (although if you want you could add a bit of fluff on her underside) but something like the aforementioned shading, or adding depth to an image helps it a lot.
 
-And probably the best advice I could give is don’t get discouraged. You’ll only improve if you practice.

I love when the artist apologizes for drawing something.

Great job for your first time!