TEXT THEMES - are fonts. You can get those at numerous places. I currently have 2000 fonts.
The TEXT TOOL is on the side panel and has a "T". Get it. T for text. It can be treated like any object. You can rotate it, and put it in the right spot. After saving it, you can Free Form Transform it to warp it a bit. And the opaque setting for that layer should give you the layer transparency that you are looking for.