Imagine if nixon had admitted to and apologized for the watergate break-in immediately after it occurred. how might subsequent events have been different?

There would be a less severe stigma against the White House and the presidency, and people would be more trustful of the government. Furthermore, perhaps Nixon would not have had to resign and Ford would never have been president. It's possible that as a result of this Carter would not have been elected as there would not have been an anti-republican outrage after the not-so-great presidency of Ford. History would be somewhat different, and America would simply trust the President more since they would have the honesty of Nixon to look back upon.
Hope that I helped!