How do you properly start overtime?

[Sendai-Horatio]

I'm noticing there's a massive power gap between even basic monsters and Rorona, Totori, and Meruru in all the new areas. How exactly are you supposed to gear up? Just gather things in the first areas without fighting until you have enough for decent stats for making weapons? Previously my gear was strong enough to survive and beat the iron golem and the dragons, but now they're not doing even a quarter of the amount of damage they were doing on the enemies in the new area. I don't really want to waste a ton of time being submitted to RNG just so I can get items with the properly quality and stat bonuses before I'm even able to fight. I tried crafting new items for both Totori and Meruru with what I had on hand with elemental damage, Attack+ and Defense+ and they don't seem to make a ton of difference. It's just real strange to have new characters added to the party for endgame and they don't do a ton of damage at all. I'm at level 55 so it wasn't like I was slacking off leveling either.