I want to upload and use a file

Upload a file

Prepare the file for upload. Make sure the file is exactly as you want it. In the sidebar, under “toolbox”, click “Upload file.” Click “Browse” next to the “Source filename:” to locate the file on your computer (the name of the “browse” button depends on your web browser). Change the “Destination filename:” to something descriptive, if necessary. Fill in the “Summary,” if necessary. Click the “Upload file” button. If it is a large file, you may need to wait several seconds for the upload to complete.

Using images and file description pages

After you've uploaded a file, you can use it in an article, with some special wiki syntax to create the link.

[[File:filename.extension]]

Your file gets its very own “file description page” within the File namespace of the wiki. You should edit this page to provide more information about the file. For example, many public wiki projects are quite sensitive to copyright issues, and so you should explain where you got the file from, and what its copyright status is, on the description page. Any other useful descriptive notes could also be added there.

Internal link to an image or a file of other types (PDF)

With the following command a user can provide a link to the file.

[[Media:name of your uploaded file |The title]]

OR
The PDF to be embedded must first be uploaded to the wiki through "Special:Upload". The namespace prefixed file name is then used between the tags to embed it in a page.

<pdf>File:Example.pdf</pdf>

With optional width and height.

<pdf width="500" height="300">File:Example.pdf</pdf>

Scroll to page 10 after document is rendered.

<pdf page="10">File:Example.pdf</pdf>

More

There is a list of other options you can use. Please visit MediaWiki for more