Beginning with the aftermath of the Kinslaying.
We visit Círdan, see the life of the Falathrim, their settlements, ships etc. This is necessary since we later on will see them besieged.
Establishing Thingol and Melian, and their court. Luthien has to shine from the very beginning, we have to fall in love with her at least a bit even if she's not going to do anything for ages and we will hardly see her (but we will show her reacting to Menegroth etc). Daeron, as I said, has to be a star. In these times of peace, he will (well, apart from Thingol and Melian, and Luthien), be the person at court that people talk about and admire. This will put him in a position which makes him develop fantasies about himself and Luthien.
Angband: SSNOP details, orcs being prepped for release. Sauron loses his job, is sent to find out what happened to Ungoliant. Morgoth does some management by fear, letting his servants know that no one has a safe position. Boldog is put in charge of the orc project. His position is under Gothmog who is put in charge of the army as operative general. I don't think a lot of time has to be spent on Angband. Boldog's relation to Mairon is probably that he thinks Mairon is a loser and he himself a winner, but they won't have much contact at this stage.
We see Eöl who has some kind of contact with Mîm. This is to establish that Eöl has contact with dwarves of all kinds, and to show that Mîm lives in what is to become Menegroth, and to show two loners. They don't have to be friends - in fact, I'm not sure that's within their capacity.
Beleg and Mablung encounter orcs for the first time. The two elves happen to come across some sorry looking beasts wandering. They run away. Suddenly the starlit dark is disrupted by three volcanic explosions to the north. The Thangoridrim peaks are created. The time of peace is over.