I'm an electronics hobbyist and I recently purchased a breadboard for prototyping. However, it seems that under it all there is simply a metal grid. If I were to run power through this, wouldn't the electricity just run through the grid and short?
The columns are shorted, rows are not. So any electrical signal will be conducted through all vertical line. Any component that is not in same vertical line will not get that electrical signal. So if you want two components to be on the same node, just place them along same vertical line.
If your breadboard includes seperate rows with horizontal lines with red/blue markings at the bottom or top, be carefull those are shorted horizontally. These are shorted horizontally because distributing power to circuit more convenient that way.