After fixing the tissue, next step would be passing them to 60% ethanol. There, you can leave them in 60% ethanol in the fridge at 4*C until the next step of dehydration (higher concentrations of ethanol, xylol, etc) and subsequently paraffin embedding.
The best approach is to fix your samples in 4% PFA or 10% Neutral buffered formaline for 24hrs at 4 deg C, wash your samples in running tap water to remove any trapped fixative for 2hrs, and then you can store your samples in 70% ethanol at 4 deg C (for atleast 6 months) untill you are ready for embedding.
Agree with the previous answers. Just take in mind that if you preserve samples in formalin for longer than 24 h it is convenient to perform antigen retrieval before incubation with the first antibody