Donald and Hillary met in the
first presidential debate (90 minutes of video)at Hofstra University, New York. Lester Holt was the moderator. The host had the full control over the questions, the audience – partly students – was expected to remain silent and not to use cameras and phones.
Hillary said "Hey Donald!" and he shook her hand, apparently confident in his immunity against pneumonia and other contagious diseases. Quite generally, I am sure it's right to say that they behaved in a much more friendly way towards each other than their voters. ;-) Concerning similar formalities and speaking strategies, Trump was attempting to interrupt Hillary more than 20 times but only succeeded once. She didn't try to interrupt him, with three failed exceptions.