There is nothing wrong using all the default settings when adding line numbers to your word document. However, if you want to change the line numbers formatting, you can check "how to change the line numbers formatting" for details. Beyond this, you can also adjust the space between the line numbers and the contents.
Step 1: This article is about to adjust the space between the line numbers and the contents, so you will need to have your document the line numbers. If not adding the line numbers yet, please refer to "how to add the line numbers";
Step 2: Click the "Layout" tab from the ribbon;
Step 3: Click "Line Numbers" and select "Line Numbering Options" from the drop-down list;
Step 4: In the "Page Setup" window, click "Line Numbers" at the bottom;
Step 5: In the new dialog box, check "Add line numbering", and change the value in the box "From Text";
You can keep the other options you have already in the document so the line numbers structure will keep the same.
Step 6: Click "OK" two times to finish.