Saving templates across an entire Team is an Enterprise specific functionality.
After creating your own custom template it can be shared with other members of your team for their use.
If your template contains proprietary information or are for private use see the following.
Steps to Adding A Template to your Team
Note: You require an Enterprise subscription to share a template to your team
Save your reusable template (Follow step 2 in the above help article)
Contact us letting us know the name(s) of the save(d) templates that you want shared with your team