Hi there!
Try changing two things:
1 - Do not use merienda.regular.woff. Try meriendaRegular.woof as the filename.
2 - Your default font index is set to 1. But if you just created one font, then it should be 0. Indexes on javascript/Rpg Maker always start at 0:
- 0 = First item
- 1 = second item
- 3 = third aitem
and so on... Let me know if making those changes made the plugin work!