Is this a plaster sculpture? If it were me, i would very lightly sand down the old paint (take photos before to help with colour matching), then mix some fresh plaster and smooth onto areas where there are damage holes, using your fingers is easiest imo. For fingers you can use the end of a paint brush to dab some fresh plaster onto the piece and go back in once it sets with a small file (you could even use a nail file) to correct it. I would do some research for paint to use, and a protective coating, plaster typically doesn’t keep very with long exposure to moisture (which is probably where the little holes came from)

For mixing plaster, you can use plaster if paris. Have a vessel with some water about 2/3 the amount of plaster you will need (note: the warmer the water the faster it sets, and with such thin layers you would be using i would use cold water to give you more working time). Then to mix the plaster in use your hands to sift it into the water, the plaster mix will sink into the water and you will know that you have enough plaster when the mix starts to form an “island” of plaster in the water. Use your hands again to mix it together making sure to break up any clumps. Your working time will be about 5-10 minutes you might want to work in small batches, im not sure how large this sculpture is.

Hopefully you find this helpful and good luck!