Do swimmers get that rear disease call amoeba because water goes up the nose when they swim?

Yes: The likely point of entry of the amoeba is through the nose into the brain. Fortunately amebic encephalitis is rare.

Amoebic disease: Infection from naegleria fowleri, the organism responsible for amoebic meningoencephalitis, is quite rare. The organism tends to live in warm, stagnant freshwater, and there are typically only a few cases worldwide every year. I wouldn't worry.