This is a relatively uninteresting Map, but its save point marks the first place you can upgrade items. Though you will likely be tempted to upgrade your Weapons, it's generally a better idea at this point to upgrade Accessories. You'll get as much or more of a stat bonus from doing so, and you won't make any future Weapons with interesting abilities obsolete. Plus, you can pass Accessories around. You only have access to a signle catalyst in Chapter 4, Millerite. Millerite can upgrade Tungsten Bangles to Silver Bangles, which doesn't seem like much, but is a pretty cheap way to get a decent HP boost (since the Silver Bangles will be created at level 4).
Of course, if you're really hardcore, you could upgrade Hope's Airwing to its maximum level (at a cost of 22,440 EXP), then dismantle it to gain a Cobaltite, which can upgrade a Power Wristband or Magician's Mark to their second-tier versions. It's probably not worth the effort, but there are a number of little tricks like this you can use to get ahead of the game.
Regardless, it pays to learn how organic and mechanical Components interact. Organic Components are worth little EXP, but increase your multiplier, while mechanical Components are worth a lot of EXP but decrease your multiplier. Thus, the basic strategy is to use organic Components to achieve some multiplier, then use a large number of mechanical Components to maximize your EXP gain. For the small EXP totals required by low-level Accessories, it usually isn't worthwhile to go for a full ×3 multiplier, especially since you cannot yet purchase more organic Components. Experiment with what you have to see what works best.
Once you're done upgrading, move on to experience a number of cutscenes. The party will split up again, and you'll end up in control of Lightning and Hope. After a short battle, they will move on to the Scavenger's Trail.
Of course, if you're really hardcore, you could upgrade Hope's Airwing to its maximum level (at a cost of 22,440 EXP), then dismantle it to gain a Cobaltite, which can upgrade a Power Wristband or Magician's Mark to their second-tier versions. It's probably not worth the effort, but there are a number of little tricks like this you can use to get ahead of the game.
Regardless, it pays to learn how organic and mechanical Components interact. Organic Components are worth little EXP, but increase your multiplier, while mechanical Components are worth a lot of EXP but decrease your multiplier. Thus, the basic strategy is to use organic Components to achieve some multiplier, then use a large number of mechanical Components to maximize your EXP gain. For the small EXP totals required by low-level Accessories, it usually isn't worthwhile to go for a full ×3 multiplier, especially since you cannot yet purchase more organic Components. Experiment with what you have to see what works best.
Once you're done upgrading, move on to experience a number of cutscenes. The party will split up again, and you'll end up in control of Lightning and Hope. After a short battle, they will move on to the Scavenger's Trail.