The best I could find is below, but it is valid only for a string. And it is not quite clear about Bold and Italic. Although there is an example for Underline, so I will try to experiment.
Unsure if there is a Font chooser / dialogue.
You could use this lib https://www.b4x.com/android/forum/threads/customfonts.85264/#content
Then possibly set up some font example labels contained in a panel, to be presented to the user.. unless there is something available.