Instead of adding spaces in front of contents, you can indent to have your contents look professional. To indent contents from left in cells, please see steps below:
Step 1: Select the cell or area you need to indent;
Step 2: Click the "Home" Tab from Ribbon,
Step 3: Click the command "Increase Indent", see below;
Step 4: The contents you selected will change.
Step 5: In case you need to indent a lot, please select the contents first, then right-click to bring up the dialog box, from the list, click "Format cells";
Step 6: Select an indent format from the drop-down list, then type the number in the box under "Indent".