OK i will try to do a step by step ....
1. Go to the panel on the left of the screen, and select the "markers" tab.
2. Scroll through the zones and find the "text zone" marker .
3. Click and drag the "text zone" marker to where you want it place, left click to place.
4. Click on the marker you just placed, and from the widget that appears select "properties".
5. Locate the "Sound0" field in the properties panel, and change the "hello world" text next to it to whatever text you want to appear.
6. Click "apply changes" at the bottom of the properties panel.
Done, now when you run test game and walk into the zone you placed it will display your text at the prompt (bottom of the screen)
Hope that helps, not sure i can make it any simpler.
i7 7700,k NV1070 8GB, 16GB 3200mhz memory, 1x 2TB Hybrid, Win10.
i5 4760k, NV960 2GB, 16GB 2333mhz memory, 1x 2TB Hybrid, Win10.
i5, NV1050 4GB, 8GB memory, 1x 1TB HDD, Win10.
i3, Intel 4000 series graphics, 6GB memory, 1x 500gb HDD, Win8.1.