An iPad cannot send or receive text messages on its own. Sending text messages requires a phone. If you have an iPhone, you can forward text messages to the iPad. The iPad will send/receive iMessages, which require data, but not SMS. See this about Continuity and how to set up Messages so you could receive SMS from your phone on your iPad. Use Continuity to connect your Mac, iPhone, iPad, iPod touch, and Apple Watch - Apple Support Click on the SMS and MMS section.
Question: Got my new iPAD today, can’t seem to send/receive text from iPAD