In Gmail, you can take notes and manage them in the same way as Microsoft Outlook.
Step 1: Login your Gmail account (please refer here to open one if you do not have an account yet);
Step 2: On the right panel of your Gmail account, click the "Notes" icon;
Step 3: Click the "Take a note" icon;
Step 4: Type the note title, e.g., "Lunch with friends", and click "Done" when you finish;
Step 5: To delete a note, move the cursor on the note and click the menu after;
Step 6: Select "Delete" from the list.