My Car battery has completely drained from sitting too long, so i put in a new battery and now nothing works.?

My Car battery has completely drained from sitting too long, so i put in a new battery and now nothing works. Everything used to work just fine until the battery drained. Windows, A/c, radio, power seats, etc.. What is the issue? By the way, I have a '99 Lexus es300|||THHIS MAY SOUND LIKE A DUMB QUESTION, ...BUT...DID THE NEW BATTERY NEED TO BE CHARGED. SOMETIMES THE BATTERYS SIT FOR A LONG TIME IN THE DEALER, OR PARTS STORE, AND THEY ARE ALL RUN DOWN. tAKE A VOLT METER, AND CHECK THE VOLTS. IF THE VOLTS ARE BELOW9 VOLTS YOU NEW TO GET THAT BATTERY CHARGED. IF IS ABOVE 12 VOLTS IT SHOULD START. IF IT IS BETWEEN 9%26amp;12, IT NEEEDS A CHARGE|||Check to make sure you have a good connection at the battery terminals, and that the + and - terminals are connected in the right place.|||Did you use a battery brush and clean the terminals and posts? If not do so|||does it have a theft protection system? If it does it probably needs to be reset since the power was interupted to it.|||what about the battery terminals, are they clean and tight? turn the key on, like your going to start it, and crawl under the car and jump across the starter and see if it cranks.|||your battery terminals are dirty and not making good connection, clean them real good and reinstall.