Definition
Expressing fear (of something) in German can be done by using the expressions (vor etwas) Angst haben, sich (vor etwas) fürchten, (etwas) fürchten or (etwas) befürchten.
While the first one is related to the word Angst, which in English means “the feeling of anxiety or dread” and in German simply means “fear” or “worry”, the latter three are related to Furcht, which also means “fear” but is a bit old-fashioned. The word befürchten is mainly used to indicate apprehension or worry about a future eventuality.
Relatedly, the German word for “fright” is Schreck or Schrecken.
Examples
Ich habe Angst vor Spinnen. I am afraid of spiders.
Ich fürchte mich vor Spinnen. I fear spiders.
Ich fürchte, das wird nicht funktionieren. I am afraid that won’t work.
Ich befürchte das Schlimmste. I am fearing the worst.