"Three Entertainments" are light-hearted, descriptive vignettes - have fun with them! If it feels right to add a trill or a glissando, do so. "Fiesta" is, of course, of a Latin flavour - lots of sunshine and good humour. I imagine it describes a party with good food, dancing and much showing off.
Enjoy this performance of "Fiesta" by the Artamus Guitar Trio; from their self-titled album available in GooglePlay, iTunes, Spotify, and many other online portals.