On the top-right of any WikiTree page including G2G pages, you should see 4 choices of drop-down boxes... the 3rd of which is "Find". After clicking that, you can scroll down the list to whatever you are looking for including people, projects, and more. When searching for people, there is an option on the bottom of the page to use Google to search within WikiTree pages. This can be a useful tool in searching for all the "Mary Smith"s that lived in "Vermont". You can also include dates or other details; any words. Regular search terms like quotation marks and + symbols function normally.
I hope this helps. If not, direct me and I'll try again :)