This is much too generic of a question, everyone has slightly different ways of doing things
You have to develop processes related to
1) what you're machining (material, desired features)
2) what you're using (tooling, tool holders, CNC machine[s])
3) what your tolerances are (provided by customer etc)
Personally my workflow looks something like for Vertical Milling (you did not mention a particular process or part type)
1) Provided file -> isolate components into individual workspaces
2) Determine an order of Operations based on the shape of the part and select a machining process (for example, 3 / 4 / 5 axis) + number of operations to get a complete part
3) Add / make my workholding in my isolated component workspace and properly position it
4) Create a CNC Setup using defined Machine + Operation Type + WCS + Model + Fixture + Stock + Program name and WCS assignments
5) Program all the toolpaths needed from my existing Cloud Tool Libary(ies) to complete that Setup adding new tooling required for the part either from Vendor libraries or custom / form definitions
6) Repeat steps 3->4->5 using Preceeding Setup Stock until I have a completed part making whatever additional workholding fixtures I need as I go with their own dedicated Setups
7) Simulate at the component + Machine Simulate final
😎Post NC Code and run part
9) Make NC Program for multiple simultaneous setups (if needed)
Quick attached picture, but again this type of generic request on "how to" is lacking some serious information. Some parts can always be held in a vise, some need special fixturing etc I don't know how to address ALL parts of the CAM / CNC workflow at once or the specific knowledge you have in doing any of these steps