Bettas are normally very easy to take care of and it’s important to know how to take care of betta fish, especially if you plan on leaving it for a few days.
Surviving isn’t thriving, though - after 4 to 5 days with no food bettas will start tapping into their reserves and enter the beginning stages of starvation.
Because betta fish have such small stomachs, they really don’t need a lot of food at any given time. In fact, it’s healthy for bettas not to have an overabundance of food at any given time.