The Spanish side have taken control of the tie with a 3-1 win on home turf but Zidane is expecting the Reds to "leave all they have on the pitch" in next week's return leg at Anfield.
He said: "Liverpool is the opponent and we know they are going to leave all they have on the pitch, I have no question about that.
"We just need to be ready and it is going to be a very good second leg match. We will need to do the same thing in the second leg.
"There is a long road ahead and we are alive. Today is the first leg but we’ll know we’ll have a second leg and our idea is to think that we go into that and the result will be 0-0.
"For us, we are happy but we have another complicated game for the second leg."
Zidane praised his players as the tactical approach to the match worked perfectly, with Real limiting their opponents while creating plenty of chances of their own.
He said: "These two sides are quite offensive and we knew we could hurt them from that aspect, so we prepared properly.
"What we did quite well was defend properly with the three in the middle and we know if we defend properly we will get chances in the attack and that is what happened.
"The first goal was quite beautiful with a wonderful pass from Toni [Kroos]."