2005 ody EX-L battery keeps draining

Okay so this is my first car I did test drive it before buying, felt and sounded sound the drive home was fine no lights, checked under the hood when I got home all seems in order however the battery keeps on draining, the first couple of nights I had it the battery stayed charged I noticed the change after I messed with the power controls (it's all powered) I tried to use the doors and a long sting of beeps started and the door wouldn't close all the way, I figured I just did it wrong, I noticed that the right side Door wasn't closing all the way or being sucked in unless the car was turned on I just want to know if it's something with the battery cause I can afford to get a new one or if it's something else, when I was cleaning it out I found a 7.5 amp fuse that wasn't blown I havent checked anything with the fuse boxes yet because I don't know much about cars and don't want to mess anything else up when the car is jump started it works beautifully everything works and no lights come on but is it something other than the battery that's the problem (I can give more information if needed).