How to fix Lawnmower that wont crank or start?

Lawnmower battery was left on for about 3 days by accident. Upon notice new battery and fuse were bought but still nothing. When key is turned on nothing happens still. I tried testing the solenoid (4 piece) with multimeter and didnt get a reading on both the bottom left prong or the top right bolt. Is it just solenoid or Any ideas on where to check next? Also when I tried to manuely crank it with a screwdriver nothing at all happens as well, no sparks. Thanks for your help!