How can I make a post that includes my students' personal information (e.g. name, etc.)?
You need to articulate more about what you are trying to do.
Example: I say Hello, <name>.
When John Smith logs in he reads it as Hello, John Smith.
When Pedro Cruz logs in he reads it as Hello, Pedro Cruz.
Ah...perhaps someone has written a plug-in or something to do that. It requires parsing the session variables and printing out the username within the context of a post field in the database. Not something moodle has built in. The only place you would see that maybe would be in the sitewide filters ...