1) When you open Creo, you should see a tab for "CadActive" in the ribbon. If you do not see it, please install it and make sure your config.pro is configured (more information here).

2) In the CadActive tab, select the Log In button. In the popup window, use the email and password that you created when your organization owner invited you through CadActive's online portal.

3) Make sure that you have the proper Creo configuration settings for Spec-Driven Piping in your config.pro, see more information (here).

4) Now that the setup work is done, we can start piping. Create a new assembly! In the Applications tab, select the "Piping" button.

5) You will see that the Spec Driven button is checked. If this is not checked (AKA - your configuration setting of "piping_design_method" is set to "user-driven" or "non_spec_driven"), you'll want to check it to pipe with spec-driven.

6) From there, navigate to the "CadActive Piping" tab in the ribbon (directly to the right of the Piping tab" and choose the "Select Spec Project" button. From there, select the project you'd like to work within from the dropdown.

7) As a final sanity check, we recommend navigating the "Diagnostic tab" to ensure your configuration settings are correct. Generally, "Master Catalog", "Spec Projects", and "Current Spec Project" will be network drive locations and "Fitting Library" will be the Windchill directory where the actual Creo fittings are located. If you have any questions or something doesn't look right, please ask your Creo administrator.

8) Now, back in the "Piping" tab, select the "Create Pipe" button. In the "Create Pipeline" popup in the "Pipeline Label" section, select the Spec, Size, and Schedule you want to create for this new pipeline. If the options are available, select values for Mnemonic and Number. If you have insulations for the given spec, you can check the box for insulation and choose. 

In the bottom "Pipeline Assembly" section, if you'd like to create the pipeline within a new subassembly, you can change the name to what you'd like. If not, uncheck the box next to name.
(More information can be found on PTC's website here).

9) Now that we have a subassembly, linestock, and pipeline created, choose the "Set Start" button and choose the coordinate system you'd like to begin the pipeline on and hit OK.

10) From there, you can use the "Extend" and "Insert Fitting" buttons to do much of the initial design work for a pipeline.