Everybody can contribute, whether it be fixing typos or fleshing out an article on your favorite thing in the Titanfall universe. If you are unsure about how to do things, look at the source text of existing articles to get an idea.
Always try to add references so people can dig in deeper and find new, interesting information!
The frontier.tf Wiki uses a Markdown variant called "GitHub Flavored Markdown", you can use this Markdown Cheatsheet as a quick reference point. It's also possible to mark up your text in straight HTML, but this should be reserved for times when Markdown is not enough.
In case two things exist in both Titanfall and Titanfall 2 a decision has to be made: Keep a single page for both or make a new one? For a character like Blisk one page is enough, but you'd want separate pages for the maps in Titanfall, and those in Titanfall 2. In this case prefix the page for the latter game like this
Titanfall 2:. Maps and Titanfall 2: Maps is a good example of this. The original always comes first, unless something is entirely new in a latter game (like Callsigns).