The camera has a built-in light meter, likely has 3 or 4 metering modes you can choose from, and is a scale that is graduated in incremental steps.
For the type of event you describe Center-weighted metering will likely work best.
1/30 is a fairly slow shutter speed for making images without camera shake blur from hand holding the camera.
A rule of thumb for camera shake prevention is to use 1/the focal length of the lens you are using. If the lens focal length is 60 mm you would not want to use a shutter speed slower than 1/60.
A related camera shake factor is using good camera holding technique - left hand under the lens, right hand holding the camera body, upper arms in against your torso, one foot somewhat in front of the other with somewhat more of your weight on the front foot.
For making photos of people I recommend a shutter speed no slower than 1/100 because people move at least a little bit, which can cause motion blur in the photo.
1/30 to 1/60 is a full stop less of shutter speed. In other words 1/60 lets in 1/2 as much light as 1/30 does.
To maintain the same exposure you had at 1/30 (built-in light meter centered) either the lens aperture or the ISO would also have to be changed to provide a full stop more (2x) light.
1/800 to 1/1600 is one more stop of ISO. On that basis, 1/60, ISO 1600, f/4 is the same exposure as 1/30, ISO 800, f/4
As far as lens aperture, one more stop of lens aperture from f/4 is f/2.8, such that 1/60, ISO 800, f/2.8 is the same exposure as 1/60, ISO 1800, f/4.
You can accomplish the same thing by changing both the lens aperture and the ISO.
Most cameras that have manual mode are set by default to adjust the 3 exposure settings in 1/3 stop steps. So a full stop change is 3 clicks more or 3 clicks less.
Those cameras usually also provide the option of setting up the camera for changing exposure settings in 1/2 or full stop steps. The increments on the built-in light meter scale also change according to the option you select.
That means you could change the ISO and aperture by 1/2 stop each to make a 1 stop change, or you could change them in a 1/3 - 2/3 ratio to make a full stop change.
In summary, your camera likely allows for very precise exposure control, and without knowing how much light you will have to work with no one here can give you specific settings.