Unless otherwise indicated, fonts at FontShop contain at least a basic Latin character set, allowing the typographer to set copy in several of the most common western languages: English, Spanish, French, Italian, German, Dutch, and so forth, each with supporting figures and punctuation. Pro packages, or ones marked explicitly CE, tend to cover these, plus more of the Central European languages that share the Latin script: Czech, Polish, Estonian, Lithuanian, etc..
Exceptions to the above rule include fonts designed primarily for use in other (non-Latin) scripts and writing systems such as Greek or Cyrillic (though these particular scripts are generally accompanied by a companion Latin). Many others however are not, including Arabic, Hebrew, Indic scripts, and character-based languages such as Chinese, Japanese, and Korean. Checking the Glyphs section of each family is the best place to verify that the characters needed to support the languages for a given project are present.