Is there ability-gating and a map?

I was playing the main game and then tried giving challenge mode a play but it did an override on my main game save. I restarted the main story again and the relic chests are already open and I can't get them again. It's like it didn't reset. I don't have the relics either...

I know you can fast-forward through dialogue, but deaths on a boss are super frustrating especially with how hard some are. I don't want to have to mash buttons to get through dialogue, and even then there are some completely unskippable animations and camera panning. I love the game, but this aspect is painful....

How am I supposed to defeat the first boss?

Thank you