First, find the tile(s?) you want to place the text event on. When you go on this tile, text will appear.
Place the event "Text" in Gameplay: Triggers and Scenery.
If this is your first Text event, leave the paremeter alone for now.
Go into Tools: Level Properties.
Click on the top bit of the white box below "Help Strings" once, wait about a second, then click it again. Type what you want the text to say. To add an enter, press @. # will make all text after it rainbow.
For the second text, assuming you want it to say something different, place the text event again, only set TextID to 1. Then go into Tools: Level Properties and edit the Second line of help strings, the one with 1 on it. See the connection? TextID 2 shows you Help String 2, etc. You can have multiple text events displaying the same help string.