I tried avoiding $800 quoted price from dealer to fix brake pads.

Bought after market pads and had a friend attempt.

Once they took the tire off, tried removing caliper, after unscrewing and giving it a couple knocks, it came off and started leaking!

He put it back immediately, and we replaced the tire as is (without replacing brake pads)

now the car is beeping, abs and esp lights on and braking feels dead in that side.

please help...

 

Lol.

Sounds like you un-clipped a brake fluid line?

Happens when you're not 100% sure on what you're doing

Funny story, my friend mistook lines and unhooked his brake fluid line for a good 10 seconds while I was getting tools when we were putting on his springs. Ahaha.

 

Woops. If you aren't totally secure in your ability to work on a car, research, and read until you are. If all you did is unhook the line, and dump some fluid just top it off, and bleed the system.

 

All joking aside... brakes are the last thing you should be "learning" on. Do yourself a favor and do the safe thing now. Tow it in and have it fixed by a professional before someone gets hurt or worse.