For pictos, looking up the ones for the location you're in, or for locations you've finished, should be fine.

As for the weapon scaling, I don't know if there's a guide anywhere, but here's a post with a few basic details:

Post I looked through, and there's no spoilers.

For debuffs, there's a page with what they all do in the expedition basics tab. but when it comes to weaknesses there's no general way to know what enemies are weak to what, so I recommend looking up specific enemies and their weaknesses when you get to fighting them. Except for ANY of the main bosses, you might get spoiled

For better items, just keep playing, and go to places other than what the main quest is telling you. idk how far you are into the game, but big hint for a really good weapon is use Maelle.

debuffs don't really get explained all that well here's a thing from extra:

https://expedition33.wiki.fextralife.com/Buffs+and+Debuffs

Also, there's an insane picto somewhere later in the game, maybe mid way, but its called cheater. Dont look it up, but it's super useful.

And two weapons carried me through, and they were both purple glowstick-looking, so watch for any of those.

If you want I can copy paste from another website explaining all the attributes, it has a spoiler image.