Nothing is explained

It makes a lot more sense if you have the context from the Soulsborne games. The series started much simpler, with (mostly) linear progression, fewer weapons/abilities, and shorter "quests." Part of the appeal of those games was the mystery, and the community that grew around solving the unexplained quests/mechanics/lore. The games were shorter, and the maps smaller, so it was easier to explore on your own.

Then with Elden Ring, it just exploded with content, built around the same game play mechanics. For veteran Soulsborne players, it plays like the next title in the series. The only really novel mechanics are the open world and spirit ashes. The downside is (at least for me), the world is so large that it's a chore to explore everything. I finished my first play through and lost the will to start a +1 game. In contrast to Dark Souls 3, where I completed at least 6 play throughs.

But if you don't have that context...yeah i'd imagine Elden Ring is overwhelming in its complexity and scale. Trying to figure out Soulsborne mechanics and navigate this giant world with little direction sounds daunting. Pitting you against the grafted scion to die immediately, and right after putting the tree sentinel in your way, was a confusing way to start the game, even for me.