This is a common problem and it's so common that the Excel team has made the solution very simple to find but unless you know what you're looking for it's unlikely you'll find it.
The answer is within Excel. Select the View tab at the top of the screen. then click the Freeze Panes button. then select either the freeze top row or freeze first column button that freezes the first row or the first column.
You can freeze both if you like. If you need to freeze multiple rows or columns you'll need to look online for information how to do that. It's a little more complicated but not much more.
Then if you decide you want to unfreeze those rows or columns you'll also find menu items that do that is well.
Once you've frozen the top row for example you can scroll down in your spreadsheet and as you scroll down the top row won't scroll with the rest of the data so you can always see your column headers. The same thing for freezing the first column then as you scroll to the right the row headers won't scroll with the data so you could always see the first value in each row.
This is a simple solution but one that's invaluable if you have a large amount of data.