From a beginners perspective, it is very important to understand the following Metering modes. These will help you get correct exposure.

Matrix/Evaluative - this is appropriate for standard shooting conditions. Your camera will divide the image in several zones for metering and evaluate the position of the subject with the brightness, the direct light, and the backlighting. It then adjusts the settings to the correct exposure for the main subject. The downside to this is; sometimes it gets the subject wrong and exposes correctly for the part of the image that is not the main subject. I.E, the background

Centre Weighted - in some ways, this is similar to Evaluative but gives greater weight to the subject in the middle of the frame. As a result, the image will be correctly exposed in the middle, but not necessarily your subject, or all of your subject.

Spot Metering - This option allows the camera to meter the area within the spot AE point frame. in most cameras, this will generally be the centre of the frame, but some cameras do allow for the point to be moved around the frame. if they don’t, you have the option of pointing your camera to the subject, half pressing or AE lock to hold the Exposure, and then recompose and press shutter all the way.

This option will ensure that your subject is correctly exposed. The downside is that the brighter areas will get even brighter and the highlights may get blown. I.E, a very white and blown out background!

With regards to flash; if your camera is set to Auto mode, and you have the flash popped up or attached, the Automatic flash setting will still see the ambient light as an extreme source of light and may not trigger, or if it does, it may not fire with enough power to light up your subject.

However, in other modes such a Program AE or (TV)shutter Value/(AV)Aperture value/ priority Modes, your camera should provide you with the option of Flash compensation where you can increase the power of the flash in small increments until the desired result has been reached.

The benefit of this is that you will be able to keep the detail of the background and also correctly expose for the foreground subjects.

Sometimes, you will find that the on board flash is not powerful enough even at the full maximum setting due to its size and power output to combat the ambient light and therefore, it may be time to consider an external flash, perhaps one that you can also use wirelessly and position closer to your subjects.

Other areas that will also help, will be to study the following links

I tried to use the "Sunny 16 rule" but it didn't work, why?

What flash guide number do I need to underexpose a "sunny" background?