Yes, you have to show funds for the whole family. Even if you want to bring them later.
In the express entry profile, you have an option to choose spouse as "accompanying" or "non accompanying". If you choose non accompanying then you will have to sponsor her and the kids later...which is a long process. And remember you still have to show proof of funds for all members. So I recommend you show them as accompanying, get them to do a soft landing after getting ppr. Send them back to your home country until you find a job and set up everything in Canada.