Is there any tips for programming text in 3D.

I'm sure adding a shadow would make it look realistic. You could use a sprite or you can have the same text with a different shade next to the original text so it looks like 3D. I am interested in figuring out the answer as well

Can you be more specific with your question? Do you want text with a drop shadow, as APotato's answer addressed, or do you want actual 3D text that can be rotated and manipulated? What will you be using this 3D text for? Keep in mind that the more realistic you want the 3D effects to be, the more complex the code you'll need to implement will be.

Have you tried YTMND style 3d? It is simple make a large bitmap text then keep scaling it down changing offset. See http://yourethemannowdog.com/ yes I know the joke is a bit old by now, but just notice how the text is made to look 3d but is not.
Edit: noticed which section of the forum I replied to. You see you would also need to change the intensity for full effect, you cannot do that on a monochrome screen and I am not sure if basic is fast enough to flicker the text. The last TI calculator I used had a slow LCD screen and if something flickers it looks like it has different shades. If you are using the new color TIs there is no need to worry about flickering parts of the text.

I want actual 3D text that can be rotated and manipulated. I want to use this 3D text to make my programs more fancier.

Well the easiest way for that I would guess; would be to sprite each letter out. Then using manipulations expand and contract the sprites to make it appear 3D. That or sprite out every 3D "stage" and drawing those to the screen.