Set your text alpha to zero. Click Key. Select alpha only (green). Click Set & Close.

Set your text alpha to 100. Click Key. Type 30 in Set Key at Time. Click Set & Close.

Type Ctrl-Shift-K. Open plus sign on Text1. Check Alpha. Click on Alpha in Channels. Scrub from 0 to 30 to see the fade up from zero alpha. To edit a keyframe, select it in the graph and change the Key Position or Value.

#XPression