Can you catch viral pneumonia a second time?

Absolutely. As already mentioned, pneumonia is caused by a large variety of viruses. Additionally, not every virus confers permanent immunity when you get it. As a result, it's possible to have viral pneumonia multiple times.
Yes. There are a variety of viruses that may trigger a pneumonia. Rsv is common in infants and may occur several times in chilhhood.Influenza virus strains can cause pneumonia as well as others too many to mention. One episode with one virus won't give you immunity to the others.