Whenever i press addin your own fonts in the settings it takes me to the web page where it says to upload your own font using the plus button next to the your fonts heading in the propeties section for text but when i open my own app that aformentioned + button doesn't exist and i can infact not add the font i wanted to add
Yep. In the latest version, you have access to the whole CC font library. And you can upload your own fonts to your CC library or from the Adobe Fonts library.
So head over to your CC app on the iPad, get your new font, then head back to Ai/iPad