Trying to make a product info tracker where i put in the price and it calculates the tax

Assuming a tax of 9%, if the prices are in column A1, put into column B1 "=A1*.09"
Copy down as much as needed.

Or you could have the tax in another cell, say D1 (as 0.09), and B1 would be "=A1*$D$1"

The $ makes sure it doesn't adjust with each copy downwards.

It should be noted that doing calculations is kind of the point of excel.

I have a friend who does financial tracking and calculations as a business and uses a calculator for everything so it’s apparently not widely known.

Maybe I'm misunderstanding your question, but isn't this literally what Excel is for?

Some people are so uneducated in the use of their tools that those that do know how to use them end up being programmers for the whole department when they were hired to do some accounting.

I mean in the same cell?

Using macros you COULD do it in the same cell, using standard formulas your have your input in one cell and your output in another. Classically the second route is preferred so that you can see the exact cost and impact of each line item, including tax.

As the other person said, you can do it in one cell, but best practice is not to. It's easier to check your work and change values if you spread it out. This is extra true for a beginner. Don't make it harder on yourself for no reason. You have effectively infinite space, you don't get extra points for cramming it in one cell.