Below are some tips about the connections to use to help get you started. First we'll look at the common types of cables used.

Connecting to a TV, monitor or projector using VGA

VGA connections are very common on windows PCs, computer monitors and on slightly older HD-ready TVs which can be used as a monitor. VGA cables carry video signals but no audio, so if you intend to play a video that needs sound you will need to either play the sound through your computer speakers or connect speakers using your computer's headphone or audio-out connection.
 

DVI connections are very similar to VGA as they too only carry video. DVI usually provides better image quality than VGA as it is a digital signal. DVI is common on projectors and computer monitors but not particularly common on TVs.

Connecting to a TV, monitor or projector using HDMI

HDMI ports are now quite common on TVs, monitors and projectors, and are increasingly common on computers. HDMI carries both audio and video and delivers high quality video and audio. However, if using HDMI to a projector or screen that does not have suitable speakers, you may not be able to get audio from your computer as the computer typically identifies that HDMI is connected and therefore audio and video is routed through that port.

Wireless connections

WiFi and/or Bluetooth are available on most computers, phones and tablets. There are many good quality Bluetooth speakers available which will allow wireless connection for audio. However if you intend to use a Bluetooth speaker for video sound, be wary of a time lag between the video and the accompanying audio. If there is face to face talking or specific audio and visual clues that need to match, then Bluetooth probably doesn't work. WiFi is more reliable and it is possible to wirelessly stream video and audio using third party hardware and software such as Apple TV, Google Chromecast, AirFrame. If your centre has wireless streaming the instructions for its use should be available there.

Apple devices

Apple desktops and laptops will typically have a Mini Display Port or a USB C (sometimes called Thunderbolt 3) port if the computer is relatively new. The exact version will depend on the specific device you use. iPhones and iPads have a lightening port (the point where you connect the power supply). To connect to projectors, TVs or screens you will need to buy an adaptor to match your device with the cable needed for the projector, screen or TV. It is possible to get adapters from USB C/Mini Display/Lightening to VGA/DVI/HDMI.

Bluetooth and Wi-Fi are also available on all apple products.

Windows devices

Windows devices tends to be reasonably straight forward in that most don't require an adapter. They will usually have VGA, DVI or HDMI port that will look the same as the port on your device/cables. Your PC may have a mini HDMI port or possibly a micro HDMI (particularly in small laptops).

Bluetooth and Wi-Fi are also available on most modern computers.

Android devices

Not all android devices are capable of connecting to external displays. Look for a micro HDMI port, if your device has one then it should be able to project to screens. Some devices use a micro USB to export an HDMI signal. This is called Mobile High-definition Link (MHL) and requires a MHL lead (micro-USB to HDMI). Devices that do this usually refer to having MHL available in the specification of the device.

Bluetooth and Wi-Fi are other options that may be available.