YOU SAID:
I need to go to the shops today and buy some hair dye
INTO JAPANESE
今日は店に行って染毛剤を買う必要がある
BACK INTO ENGLISH
Today I need to go to the store and buy a hair dye
INTO JAPANESE
今日は店に行って染毛剤を買う必要があります
BACK INTO ENGLISH
Today I need to go to the store and buy a hair dye
That didn't even make that much sense in English.