If you grew up in the US you'll probably still get clocked as a foreigner, even if you have family from there/are a native speaker. Especially in a small town/more rural area. In a big city if you are fluent you can blend in better.Sí yo hablo español muy bien
but if you just exercise common sense you'll be fine. It's like anywhere, be aware and don't flash wealth/act like a mark and no one will bother you usually