The rpx package will get you started with downloading data from the ProteomeXchange repo (which also contains PRIDE data). In terms of normalisation, it will very much depend on your data. As a starting point, I would suggest to have a look at the RforProteomics package - the vignette provides an overview of some of the functionality in Bioc for mass spectrometry and proteomics data.
Hope this helps get started. Don't hesitate to get back with more precise questions.