Gloucester is like that dad who always manages to embarrass his offspring by saying something incredibly inappropriate in public. Here he says, right in front of Edmund, "yet was his mother fair; there was good sport at his making." Or, in other words, "his mom was super-hot and good in bed."
In case you missed it... Edmund is, in fact, a bastard. This is an important plot point.
Retiring from public office because you feel you're too old and feeble to take care of business? Not a bad move. Dividing your kingdom up between your three daughters to prevent any internecine squabbles? Understandable. Forcing your three daughters to participate in a public popularity contest to find out which of them loves you the most? Ehhhh...
Cordelia's "nothing" is the shot heard round the world as far as King Lear is concerned. All the subsequent trials, tribulations and tragedies could all have been avoided if she had just gritted her teeth and said "Oh Daddy, I love you best of all!" But noooooo, she has to be all principled and reasonable.
If she hadn't said "nothing", Lear would have gone and lived with her. She would have taken care of him as his dementia set in, everyone would have lived happily ever after, and the audience would have been able to go home after fifteen minutes.
I can't remember where I stole the "loyal rear" gag from - undoubtedly some actor's reminiscences of a not-uncommon verbal pitfall similar to the famous "Good Hamlet, cast off thy coloured nightie" trap in Hamlet.
Of the three truly decent guys in King Lear, two of them are in this scene: Kent and the King of France. We never see the King of France again, but you have to admit he's a sweetheart. Cordelia should have just gone off with him and never looked back.
Goneril and Regan are collectively known as the "bad daughters" or the "bad sisters", but of course there is very likely more to them than that. Let's face it - their father has not shown himself to be particularly reasonable and loving, so it's a good chance they have every right to be worried about the prospect of him coming to stay with them long-term.
Anyways, that's the first scene! Fortunately for me, not all scenes are quite as long and involved as that one. Tune in again on Friday and we'll see how Edmund (THE BASTARD) is doing.