First off welcome.
Post your config for the message and we can work from there. See below for how to post your config and preserve the formatting. YAML is very sensitive to formatting so it helps to post is properly so the users here can check it.
HA doesn’t really do much until you start adding components and sensors and writing automation to work with those components and sensors. Its extremely powerful once you get rolling but the first steps can be hard. Lets get your messaging example working and you can see how it all works.