1999 Mazda protege es 1.8 l engine?

car was running fine then the battery started going dead so i would charge it every night i figured the alternator was bad but i bought another used battery for it and after changing the battery the car wont start . i tried using starting fluid and got nothing.i pulled the fuel line off and had no fuel, i pulled the spark plug boot and coils and i had no spark. i put the battery in correctly Ive changed many batteries and i didn't get the cables backwards and i checked all the fuses and they were good. i have no clue what to start checking or replacing please help.