To save your life and stats, you have to register. Type /register and you will be asked to enter and verify a password. Once you are registered, your Current Life (if you are alive) and your Total Stats will automatically be saved when you leave the server. 

When you rejoin the server using your registered nick, a box will pop up prompting you to enter your password to login (if the menu does not pop-up, use /login). After you successfully enter your password, you will spawn at a random location on the map if you are a civilian, at a police station if you are a law enforcement officer or in your home if you quit in there. 

When you die in NG, you will have to pay Medical Fees. Medical Fees are based on your total wealth and the Medical Market rates. The more total wealth you have, the higher your Medical Fees will be.

To prevent losing this large amount of money, all of your weapons and specialty items including permits and fish coolers, you can buy up to 5 Life Insurance policies at City Hall. 

Finally, if you are registered, you can view numerous stats using /stats.

Saving Your Stats / User Accounts Commands:
/register - Register a new account
/login - Open up the login box
/stats - Look at your own stats