If you are new to watching returns, here is what to expect. A state won't know the results until the polls close. The tallies for candidates are hidden everywhere before then to keep one side from leaking the results to motivate everyone else. Votes in precincts, be it boxes on Election Day or Early/Absentee votes, are counted by counties. They report those numbers to the state election boards (roughly since every state is different.)
Some states have been counting the 100 Million votes before today and some have not. It has ALWAYS taken states DAYS to count all of the votes. What we often see on Election nights are projections by media outlets and NOT actual counts. The most accurate data is on a state or county website and not a media outlet.
If it is a blow out one way or the other, we will see those trends in the early reporting swing states like NC, GA, or FL. It is usually safe to judge a trend between 10 pm and 12 am on election night unless it is close.