Due to the expectation that Las Vegas has a certain danger level, the city has an increased police presence and various establishments also employ private security. This actually makes the city safer than you would think but still you should be careful.
Vegas is a place of extremes and it advertises as such: people go there to gamble, drink and- realistically- do other illicit things in excess. Extreme actions create extreme reactions. You could encounter some very drunk and high individuals. You could encounter someone who just lost all of their money in a casino. Not every interaction is going to go badly but it could. Muggings are not uncommon nor are drunken brawls.
Stay in populated areas and remain with the people you’re staying with. If somewhere looks seedy or you feel uncomfortable- leave. Vegas has more options than you can feasible explore unless you stay for a very long time so explore the strip AKA the places where it is guarded and there are the most cameras.