I think the big caveat is that by becoming a German citizen, you must renounce your American citizenship. Dual citizenship is allowed by the US in many cases, but in this case not by Germany. (Unless both parents were German citizens).

For example, my father's paternal grandfather was born in Wuerttemberg in the 1840s and emigrated to Iowa, making my father eligible by German law for German citizenship (and he remains eligible at age 88). However, because my father acquired his American citizenship jus sanguinis (both of his parents were US citizens) rather than jus soli, he would have to renounce his US citizenship to claim his German citizenship.

If the OP's parents were both German citizens, and the OP acquired American citizenship only jus soli (meaning neither parent was ever a US citizen), then OP may have dual US - German citizenship. In other cases, German naturalization requires renunciation of US citizenship.