Missing text messages on ipad

There are two very different types of text messages.

• iMessage. These are sent to/from other Apple devices. Your iPad gets these if you have activated iMessage at Settings > Messages > iMessage. If you get an error when trying to activate iMessage or FaceTime - Apple Support
• SMS text messages. These are sent to/from cellular telephones. Your iPad is not a cellular telephone and cannot send or receive SMS text messages. However, if you also have an iPhone, you may use it to see these messages on your iPad. How to forward text messages on your iPhone - Apple Support

Check Settings > General > Software Update on the iPhone to be certain you’re running the latest iOS version.

Read the “How To forward...” thoroughly, completely, and carefully. Pay attention to each and every detail. You said you’re a novice, but if you don’t catch each detail, someone here would have to throw a whole lot of questions your way. “Did you...”, “Have you ...”, etc.