YOU SAID:

i need to shower and then get ready before tonight

INTO JAPANESE

シャワーを浴びて、今夜の前に準備をしなければならない

BACK INTO ENGLISH

I have to take a shower and get ready before tonight

INTO JAPANESE

今夜までにシャワーを浴びて準備をしなければならない

BACK INTO ENGLISH

I have to take a shower and get ready by tonight

INTO JAPANESE

シャワーを浴びて、今夜までに準備をしなければならない

BACK INTO ENGLISH

I have to take a shower and get ready by tonight