but I'm trying to create two separate cells that always equal each other no matter which cell I input data. How can I do this? Is VB the only way?
Yes, VBA is the only way to do what you want, not to mention it would also want to be associated with the change event.

Can I say anything to discourage you from doing this? IMO, a spreadsheet works best when each cell does one thing: input, processing, or output. When you try to get a cell to do too much like this, you unnecessarily complicate your spreadsheets.

Here's how I'd do this: designate one of the two cells as your input cell. Label it, highlight it, etc so you know that that is the cell designated for this input. Cell two can have a simple =cell1 formula so that cell two reflects cell 1's value at all times (if needed, you can protect cell 2 so that it cannot accidentally be overwritten). This gives you a very straightforward spreadsheet without any unnecessary complication.