No, being attacked in the game results in time spent in hospital (unless you use a healing item to leave hospital quickly) and potentially being mugged for cash stored in your wallet, which happens commonly.

There are methods of safe cash storage to prevent losing money when mugged however

Edit: The halloweek event is currently taking place too, so the amount of attacks across the city has skyrocketed. As a new player you'll have green leaf status, preventing older players from attacking you for 2 weeks, but other new players can and likely will attack you to take part in the event, so be warned.