You can catch up on text messages you missed, mark messages as unread, and pin and unpin conversations to prioritize messages in the Messages list.
If you receive messages while you have notifications paused or you’re away from your iPhone, you can jump to the first message you haven’t seen in a conversation.
Go to the Messages app on your iPhone.
In the Messages list, do one of the following:
Swipe right on a conversation to mark it as unread.
Drag right and tap on your iPhone.
In the Messages conversation list, tap Filters, then tap Unread Messages.
You can pin specific conversations to the top of the Messages list so the people you contact most always come first in the list. Pinned conversations appear as larger icons at the top of your messages list.
Go to the Messages app Block, filter, and report messages on iPhone