You can setup as many locations as you need as pick-up locations. But in order to do this, you need to set up a few things:
Add a Directory Profile and Location
Start by setting up a new directory profile as a Brand/Warehouse Location.
Once this profile is setup, you can then add a new profile location.
Fill in the information about this location, including the address, open hours and contact information.
Once this location is in place, you can now assign the location as a pick-up location in Commerce Settings.
Setup a Pick-Up Location in Commerce Settings
Go to Sell > Commerce > Commerce Settings and you will now see this location avaialble to select as a pick-up location. To select multiple locations, hold the control key.