give you my take

First off, I've been trying to get the warm side of his tank to around the high 80s or so, I'm using a digital thermometer so I'm sure it's reading accurately but the warm side is only around 80-81. Is there an easy fix to this? I have a heat pad on the bottom of the tank as well.

you really want the warm spot in the cage to be between 90-94, im guessing your heatpad is not being regulated right now, so you need more heat, heatbulb will most likly do the trick, but you need a thermostat. like said above there are plenty to choose from. my thermostat (helix) allows me to plug in more than one device, i would put both the heatpad and heatbulb on the thermostat if you can.

Lately he has seemed very aggressive, at first I was able to take him out of the tank easily, he didn't mind and when he came out, he would crawl up onto my arm and just relax. Now, whenever I go to handle him he just seems irritated and slithers away and doesn't like to be held. Is there something I'm doing wrong or should be doing when handling to make him more comfortable? lots of reasons could cause this, first thing i would fix... see below

And I wasn't too sure on how long to leave the lights in the tank on. My friend owns a Ball Python as well and at times she'll turn them off or on. The lights in my tank have been on 24/7 because if I turn them off, the thermometer drops to about 75 quickly and I don't want to make him sick or unhealthy from lack of heat. What do I do? this is the first thing you need to fix, your most likly stressing the little guy out. most people 12 hours on, 12 hours off or just no lights at all, BP arn't like bearded dragons they don't need special light bulbs for UVA and UVB light. but since you got the light, why not use it, you can get a mechanical plug in timer from home depot or store like it for 10 bucks.

I've been keeping the humidity around a reasonable 50% mostly and trying to make sure it doesn't go under that range. I have only been using a squirt bottle, called "Zilla - Humidifying Spray, Tropical Mist." - "Helps prevent dry skin and shedding problems, Fortified with rich emollients and Aloe Vera". The store I had bought him from told me I should use this to keep the tank humidified, but if there is a more effective or better way to do that, that would be nice.

what ever that stuff is, you don't need it, just use plain old water, since you got 1 snake, dollar store spray bottle will work perfect, just fill it with water and leave it in the reptile room, its doesn't have to be hot water like said above...room temp is fine. humidity isn't a big issue like everyone makes it out to be, your big indicator that your doing things right is a nice shed. just make sure its somewhat humid in there, i only mist my ball pythons when i see their in shed, but i have them in plastic tubs, so the water bowl keeps things humid enough, most likly the thing you got reading humidity for you isn't very accurate eigher, just look for good sheds. im assuming your using a screen top glass tank? once you got the heat bulb or CHE or w/e, cover the rest of the screen with a rag to keep humidity in. allow more or less air flow as needed.

I set-up his tank with a hide on each side and a water bowl in the middle, but I'm thinking I should buy a larger water bowl since this one seems a little to small.

up to you really, i just use 1 hide on the hot side and water bowl on the cold side.