Text Question

I'm using Photoshop, which is new to me because until my old computer crashed I had only been using PSP. Whenever I try to use the text tool, nothing shows up. The little flashy line isn't there, and the text itself doesn't show up on the image, but in the layer properties it names the layer what I wrote. I've made new images and typed without adding any layers, and it has showed up. But merging my layered images doesn't do anything. I've tried changing the font size, colour and type but nothing is happening still. Is there anything I could do to get my text to show up?
Thank you