Although many street photographers prefer to use the camera in manual focus mode, another option is to use constant autofocus, in order to follow the moving subject and capture the action.

As for the shutter speed, there is also no definite rule. If you want to capture the action, you can use a speed of 1/400. If you prefer to add some blur and you know steady your hands, you can slow down to 1/15.

If your camera doesn't have a very good autofocus mode then it might be difficult to use a very shallow depth of field like f 1.4, so you might want to consider you know stopping it down to f 5.6 f 8 and that will increase your depth of field and increase the amount of area (zone focus) that you'll potentially get in focus.

In street photography, imperfections can be an improvement if your image tells a good story, then don´t care too much about them.

Sometimes you might be confronted with a scene that is very visually stimulating and you want to take a photo of it because it looks aesthetic right. What Pat suggests to do is work the scene right, stay there for 5 to 30 minutes and really understand how things, like the light, are changing and moving and how the flow of people are walking through that scene.

Street photography is about the documentation of the human condition. You know things like light and weather are certainly a part of that: umbrellas on a rainy day, hard shadows at high noon, low light in the early morning, the cool hues of blue hour, sunrise or sunset. So don't be afraid to shoot at any time of day and in any weather conditions.