Did I just break my Nikon D50?

I was messing with it because I was trying to get it to do a long exposure thing which I can't figure out how to do and the manual makes no sense.Um, but when I tried to take a picture after trying to do what the manual said, the camera started beeping really loudly and the little light in the front started flashing. Oh, and the D50 says that my SD card has 68 photos left to take in its memory, but before I started messing with the camera it said I had something like 138…

I should just not be allowed to handle technology haha

The size of the pictures taken got modified when you made the change. Say you have a shed. You can store 100 medium-sized boxes, but if you had very large boxes, you couldn't store as many.

Think of the pictures as boxes, and the shed as your SD card.

You can either:
Change the settings back, not take as many pictures, or get a bigger SD card.

You're bored with the Very long exposure and tried to speed it up? (Joking) Since I don't know what EXACTLY you did to your camera can't tell you any advice… But Here Is something UNIVERSAL even you can make… Take your manual, read carefully step by step, and see How could You reset your camera settings (e.g. To factory settings)… There's gotta be something in your manual! (e.g take out your batteries for 24h, or something else) .Next with the memory card, make a backup of EVERYTHING on it and then give him a format from windows… Those steps should give you a nice camera similar to the one from the factory (at least at settings chapter! Hope you gonna fix IT… But If you don't fix it then You're right You should be restricted in using HI-TECH Gizmo!

You did not break it. What you did do was to set it to selftimer and change the picture quality or size setting. Most likely you have it set for a Large imag size and High Quality. That will use up more memory card space but i would leave it set that way for the best photo results. Buy more and larger memory cards as they are cheap. Also do not use your memory card to store your images.
Just turn off the self timer and you'll be good to go.