Most of the settings you’ll want to change in Windows 10 are in the Settings app. Settings is organized into the separate System, Devices, Phone, Network & Internet, Personalization, Apps, Accounts, Time & language, Gaming, Ease of Access, Search, Privacy, Update & Security, and Mixed Reality (if available) categories. You can click/tap on a category to view and change more settings for that category.
If Settings is crashing or not opening, you can reset and/or re-register the Settings app to hopefully fix it.
This tutorial will show you how to reset and re-register the Settings app for your account in Windows 10.