Usually Sunday afternoon is the lightest in presentations offered. But, it all depends on your interests. I have friends that are excited for the Sunday afternoon Teen Beach Party 2 Dance Party. Not my thing.
It is actually easier to get into the large presentations than the smaller ones, in a way, because there are so many seats. Not that you can just pop over at the last minute, but it is not that difficult. I usually keep an eye on the lines for things I am interested in, and jump on when it starts to build. (or get a Stage Pass, if possible).
I think Friday will be Legends in Hall D23, then the Animation one in the afternoon. Legends is popular.
Saturday, I am all about the Studios Live Action in the morning, no time announced yet, and Parks and Resorts in the afternoon, both in Hall D23. I think the Live Action one will be a huge draw, with Marvel and Star Wars fans, like me. But they have several other panels and events at the same time, to help spread the crowds out. The Broadway event will be amazing, and I am bummed I will miss it for the others, but that is how it goes. And Pixar has some going on, too.
I thought they might announce a Playmation one for Sunday, similar to last time when they did Infinity. But nothing yet on that.