Hello Jen-Colt.
Welcome the Apple Support Communities. It seems you are unable to send an iMessage with your new iPod Touch. I'm happy to provide you with some direction to resolve this.
If the number you are trying to send the iMessage to is not an iMessage enabled number, then this is expected behavior as an iPod Touch cannot send standard text messages unless you have an iPhone with the text message forwarding feature enabled for your iPod.
If it is an iMessage enabled number, then I recommend following steps in these Apple knowledge base articles:
Use Messages with your iPhone, iPad, or iPod touch
If you can‘t send or receive messages on your iPhone, iPad, or iPod touch
Learn more
If you still can't send or receive messages, contact Apple Support.
Have a nice day.