Give me the formula to grab data from an excel spreadsheet and use it in another. Take into account that the office version is 365.
There are multiple ways to grab data from an Excel spreadsheet and use it in another. Here's one way to do it:

Open the source Excel spreadsheet and select the data that you want to use in another spreadsheet.

Copy the selected data by pressing Ctrl + C or right-clicking and selecting Copy.

Open the destination Excel spreadsheet where you want to use the data and select the cell where you want to paste the data.

Choose the Paste option that works best for your needs:

To paste the data as a simple copy, right-click the selected cell and choose Paste or press Ctrl + V.
To paste the data as a link that updates automatically when the source data changes, choose Paste Special from the right-click menu or the Home tab, select Paste Link, and click OK.
To paste the data with specific formatting, choose Paste Special and select the desired options.
Save the destination Excel spreadsheet.
Note that the exact steps may vary slightly depending on the version of Excel you are using, but these general steps should work for Excel 365.
To do that you can follow this steps in Excel 365:
1: Click in the cell where you want the pulled data to appear.
2: Type = (equals sign) followed by the name of the sheet you want to pull data from. If the name of the sheet is more than one word, enclose the sheet name in single quotes.
3: Type ! followed by the cell reference of the cell you want to pull.
4: Press Enter.
5: The value from your other sheet will now appear in the cell.

Giving a concrete example:
If you want to use the data of an sheet called my sales in cell C3 you can write the following formula in the desired destination cell:
='my sales'!C3
After pressing enter the value is copied to the desired location.