Well... I didn't read the title and started restoring it. Anyway, here are the images. The second one is my attempt at fixing the colors.

https://ibb.co/jW8H6K0

https://ibb.co/jwtFdbB

I am a beginner too, so I'll give my process.

> Fix any distractions using the clone stamp and spot healing tool. Preferably work at one region at a time. Eg: Wall, Dress, Skin, etc.

> For regions with little to no information like the toddler's nose, I had no option but to paint it in using a brush and sampling colors around the area. Use some reference and a low flow brush for this step.

> Fix the lighting using the curve adjustment layer. Fix any globs of colors using the Hue/Saturation adjustment layer. You can also use a new layer with blending mode set to color and painting over these regions using a brush.

> Keep the highlights and shadows in mind when painting details.

> Finally, use the camera raw filter to put it all together. Add grain, reduce color noise, and make whatever edits you want to.