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