Under Content, you can make an Entry Form page to capture any information you like (Content > Entry Forms). A common use of Entry Forms is for Free Agent Sign Up pages for Adult Sports or Coach Sign Up pages for Youth Sports.
After you create the Entry Form page and add it to your Site under Content > Site Pages or Content > Sidebar Links, periodically you should go to Reports > Report Exports to run an Entry Form Responses report of the people who have responded to the Form.
In the case of lists like the Free Agent Sign Up entry form respondents, you can post the list to your Content > Downloads page. Once it is there, then you can send out a Communication to Coaches and use the Links feature to link to the file on your Downloads page. You can also create a News Item or edit a Custom page in your Site and use the Links feature to link to the Downloads page file. You can even edit the Entry Form text area and add a link to the Downloads file there.
Here is a link to an article with more information about how to use the Links feature:
https://teamsideline.zendesk.com/entries/20664953-downloads-page-links-tool-bar-drop-down