Please, do not encrypt it with File Vault, do create a good login password. I suggest a sentence, it's difficult to create a multi character password that's memorable so sentences have become quite popular eg. TwoPlusFiveis7 or 2ToTangoForTwo or even 2EasY4Me is still 8 characters has upper and lower case letters and 2 numerals. Avoid symbols, they can be problematic. A good login password will provide all the security you need for your device and a nonsense sentence is so much better than; your name, your birthday, 123456789 or mypassword all of which are incredibly common even today.