Home is set by microswitches on each axis and is fairly repeatable. This is fixed, nothing you do will change that. After being powered on the machine won't do some things until you home so it knows where it is.
Your origin (zero point of each axis) is whatever you set it to. You could set it to home, or to any location within the travels that is a fixed offset away from home, which it sounds like what you want. You do this by setting offsets in setup, where you define the distance offset from home that you wish your zero to be.
If you just powered it up:
1. Home all
2. Zero all
3. Setup>offsets select your offset to use (this will zero again where you want it)
4. Touch off your Z for the bit and stock you want to use
One you decide where you want to place fixtures etc on the table and make your offsets you can make a reference drawing (rectangle) in a layer that shows where your table travels are in relation to your origin. This way you can check to make sure you are not exceeding your travels in locating your parts.
For my 054 I have my origin set a few inches north of front and center to make it easy to reach things. This means my part will only be machined in the positive Y direction but both positive and negative for X. It's totally up to you, but you need to match cad space with where you've set your offset/origin.