I don’t know how far you got into the first one but they are pretty similar games in my opinion. Everything that was good in Octopath 1, got better in Octopath 2. So: music and sound design, still amazing. Art, it’s the same HD-2D style that’s popular nowadays and Square is good at it. Character storylines are still mostly separate and not extremely complicated. The endgame scenario of Octopath 2 is more fleshed out than the hidden/True Last Boss of Octopath 1. I had a lot of fun in the endgame but in my opinion it was still too short.
The battle system is even more broken than Octopath 1 and largely revolves around setting up a team that can generate lots of BP, stack all your buffs onto a single character and maybe a debuff on the boss, then break it and deal 10k or 100k damage in a single round with your strongest attack. I think with certain setups it would be possible to deal 2 million damage in a single break. No boss has that much HP, though.
You still get powerful by exploring the map for gear and stealing/path-actioning good items from the end game cities. Grinding isn’t really necessary to beat the game but there are multiple setups that can turn trash encounters into 1-button wins.
The sub-job system is more flexible in Octopath 2. In addition to Break, characters have unique Latent Power “limit break” skills. There are so many ways to build a team that works well and part of the fun is figuring out what skills you can spec onto your characters and combine in order to win the game. That was also the case in Octopath 1.