Not sure if it was said before, but if one feels like that, the best course of action is probably to not post online until one is ready for at least some feedback.
I'm the type who can only improve with critique, whatever it is, and I get something useful from most (except blatantly agressive ones with no actual will to help).
But I know some people do not as well with critique and have to adapt.
However, if there is a complete rejection of critique, especially in a beginner, I see it as a a bit in contradiction with the decision to post online. Plus, on Tapas, you can turn off comments, which gives a compromise for people who don't wish to hear anything from readers.
If there is a huge confidence problem for a beginner, or a feeling that passion for the art they are making is still fragile... there is still the possibility to develop the art and confidence a bit before going online.