This chapter has explained what your choices mean. The companion Implementation Manual explains how to make them, field by field and in dependency order: creating number sequences and what their prefixes become on your documents; defining units of measure and their conversions (and why a wrong conversion quietly corrupts stock); setting payment terms and credit terms and how they print; building tax codes; and the rest of the System Setup machinery that Chapter 16 tours at the user's level.
Keep the division in mind as you read on: when a module chapter says a setting "shapes" a workflow, it will explain the shaping here and point you there for the setting.
See also: 1.2 The menu — finding anything · 16.3 System Setup — the directory · 16.6 Setup Progress — the checklist that watches your setup