I can't use the Auto-focus mode in my Nikon d3200?

It all started when I had an out-of-town trip with friends when I tried to take a photo of the falls and beaches and trees with the sun flares. I thought it either got too much sun exposure or or something is broken inside or my camera really needs cleaning, which i don't know how and i can't find anyone who knows how. Also, I can't set up the White balance, ISO, AF-area mode, etc in the Shooting Menu. I tried resetting all but, still, nothing. I also can't bring it to the city to get cleaned(i'm in a town--fare is so much for me), i can't afford it. So right now, I only use the manual focusing, which gives me blur captures(not good in taking pictures esp in action) and my photo quality changed. I love taking pictures of every moment that happened and having nice landscape pictures satisfy me and I know i'm very careless in taking care of the camera. I need help.

From what you wrote you may have gotten sea water with salt in your camera. You can check with a pro about repairs but it may be too late. But do check.

And, start taking better care of your gear.

No camera will stand up to excessive abuse. Sadly, it sounds like you broke it.

Have you checked the Autofocus switch on your lens? See page 14 of your manual on setting the lens focus mode.

If you don't change lenses, it is unlikely that you need to clean the camera.

Page 189 of your manual tells you what to do if the camera quits responding.

Are you trying to set up while in Auto mode? Try various modes.

Manual focus is a learned expertise; don't be discouraged, get help.