If you are a Team Coach/Manager, then edit the role of one of the parents or yourself and make that person a Team Parent on the Team Site -- that enables the person to go around to all the parents at the first practice or game and get everyone text enabled -- but anyone can do it -- parents can edit their own information, or a Team Staff member can do it.
If you do it for yourself, you'll know it's easy: just 1) sign into your main site, 2) click the Team Site link, 3) go to the Team Site "Roster" tab, then:
- Click the edit icon next to a name.
- Under the Phone section
1) enter your cell phone #,
2) check the box to "Enable text messaging for this phone number",
3) select the Mobile Provider from the drop-list. - Click Save.
It's worth doing because texting from TeamSideline Team Sites is both free and unlimited.