When you add an outcome or progress tracker to a project, it means that

You can post stories that contain progress relating to that progress tracker
The progress tracker and/or outcome appears on the project page in the Progress Panel
You can set project-level targets for the progress tracker

Note
You need to create a project first before you can add goals and sub goals to a project

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Watch the walkthrough:

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To get to the Edit page of the Outcome or Progress Tracker (metric), find the metric in the Metrics App by using the pagination. Then press Edit within the Actions dropdown on the right side.
On the Edit page, open the Advanced section
In the Projects field, enter the names of the projects you want to add the Outcome or Progress Tracker to
Note: you cannot add Multiple Choice Trackers, Achievement Trackers or Numerical Trackers to a project directly. You must add them to an Outcome and then add that Outcome to the project(s).
To ensure that the progress tracker is available when you post updates, go to the Project Targets page of the project you have added the progress tracker to. Click save. Now you have done this, you will be able to post updates that contain progress tagged to this metric.

From the Explore Goals page

The Explore page contains Progress Trackers that can be added to your projects
The Add To Project button appears next to every goal and sub goal Activity Tracker, Attendance Tracker and Outcome on the Explore Goals page
Click the Add To Projects button.
A popup appears
Select the project(s) you want to add the metric to
To ensure that the progress tracker is available when you post updates, go to the Project Targets page of the project you have added the progress tracker to. Click save. Now you have done this, you will be able to post updates that contain progress tagged to this metric.

A collection is a group of Progress Trackers, Outcomes, Surveys and Strategies
Each Progress Tracker within the Collection has an Add To Project button on it
Click that button to add the Progress Tracker to one or more of your projects
To ensure that the progress tracker is available when you post updates, go to the Project Targets page of the project you have added the progress tracker to. Click save. Now you have done this, you will be able to post updates that contain progress tagged to this metric.

Every user has a Goals Library and if you are an Organisation Admin you also have an Organisation Goals Library
Every Progress Tracker in the Library has an Add To Project button on it
Click that button to add the Progress Tracker to one or more of your projects
To ensure that the progress tracker is available when you post updates, go to the Project Targets page of the project you have added the progress tracker to. Click save. Now you have done this, you will be able to post updates that contain progress tagged to this metric.

A strategy is a group of Progress Trackers and Outcomes grouped into a template that can be easily added to a project.

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