Do you just mean that the window is off the screen? You can just drag it from the top bar, where the tabs are to the middle, or click Windows Button + Up Or, do you mean that the screen has a black bar to the left?
Try a quick restore: (1) Slide the Hold switch to the locked position and then slide it to unlocked again. (2) Press and hold the Menu and Center (or Select) buttons together until you see the Apple logo (about six to eight seconds). You might need to repeat this step.
Your motherboard will have shorted itself. The water will allow certain components and connections to connect to others when they are not meant to, and broken the motherboard. Water damage fix usually involves dipping devices in 99% isopropyl alcohol, as this forces out the water. Then it evaporates. This may be a fix for you, but most likely the damage is already done and certain chips are broken. A lot of computer repair shops actually have no clue about computers beyond installing an operating system and drivers, so it may not be so easy to find a computer shop that can perform repairs on specific chips.
You can do this without any computers. Download Google Photos on both. It will sync all your photos to the cloud, and it will appear on both devices. There will be a circular sync icon on each photo as it syncs, and once it disappears, it means it is now stored on your google account.
There are multiple chips around the screen connector and battery connector. Sometimes one of these can get ripped out. Another problem could be that you have put screws in the wrong places - this can cause the logic board to flex and become damaged otherwise, which is an expensive repair. It is difficult to determine what the issue is here, but didn't you mention you fitted a new battery? It is extremely common for these cheap knockoff batteries to be faulty, just try a new battery.
I have had issues before with the fan/temperature before, try resetting the SMC: (1) Shut down the computer. (2) Plug in the power adapter. (3) On the built-in keyboard, press the Shift, Control, and Option keys on the left side and the power button, all at the same time. (4) Release all three keys at the same time. (5) Turn on the computer.