You don't have to create all the sounds for your mediascape yourself. You can find sounds and music on the internet.
Getting the sounds onto your computer is called downloading.
Sounds may be in the form of .mp3 files, .wav files, or other formats
They may have a download button you can click on, or you may have to right-click your mouse on the file and click on Save target as
Both ways should copy the files onto your computer, and let you choose where the files can be stored.
If you want to move the sound files to another folder, right-click on the files and then click on Copy.
Go to the folder you want to keep the sound in, right-click again, and then click on Paste.
You will need .wav, .mp3 or .ogg files for your mediascape.
Remember that some sounds and music you find on the internet belong to other people, and you may not be able to use them in your project without their permission. Ask your teacher or helper about what you are or aren't allowed to download.