After creating your first blank document, you need to first save this document so that any editing made in the document could be saved. Here are the steps which tells how to save your document file in MS word 2019.
Step 1: Click on file tab placed at left top corner of your document, you will get a screen as above showing option to save your file. There are two options first is (save as) and second is (save).
Step 2: Click on (save as) option and select storage location where you want to save your document.
Step 3: After selecting location to save your document, you will get a new window shown below asking to give a name to your document.
Step 4: Give a name to your document or file as per your choice and finally click save. The file will be saved at a location you have selected in the earlier steps.
These were the steps which guide you to save your document file in MS Word 2019