For normal leveling, just follow the usual pattern. Lorencia -> Dungeon 1 -> LT7 -> Tarkan.

This pattern makes it very easy to level. When possible use panda ring and panda pet from the X Shop to speed things up. Each reset will give you 1 credit, so just doing a handful of reset should net you a positive on the investment!

Once you've reached around 20 reset, focus on master level! That will make normal level resets much faster by being able to access level 400 maps while being on normal level 1.

When you reach this point, Ferea is the go-to spot! Resets fully buffed can take about 1 minute, so you should be able to cook around 100 normal resets in about an hour or so!