Before your protagonist faces their biggest challenges, give the reader a clear picture of what they're up against. In the opening of Raiders of the Lost Ark, Indy navigates the temple by avoiding pressure plates, swinging over a crevasse, and stepping carefully across the booby-trapped floor. With each step, we see what happens if he gets it wrong. So when the temple collapses, and the boulder comes, the anxiety is real because the viewer knows what it takes to escape.
What makes the scene work so well is that it's pulling double duty. It establishes the obstacle and the character — that Indy is intelligent, capable, and brave. We didn't need to be told any of that, because we watched it.
For your opening sequence, tell the reader once what your protagonist is walking into, so when they face similar circumstances, the reader knows what they're up against. And how they handle those circumstances will reveal character, all for the better.