Purchase a bus ticket to Santa Rosa de Copan in San Pedro Sula or Tegucigalpa. Then transfer to a bus headed to Gracias. From Gracias, there is one bus daily to La Campa leaving at 12 noon. Cost is 15 lempiras ( or around one US dollar). Another option is to take a motortaxi for $10.00. The bus returns to Gracias at 6:30 am the following morning or you can return via motortaxi.
But La Campa is well worth an overnight stay - hotels are a bargain, the skies are clear and perfect for stargazing and the people will welcome you wherever you go.