I often have trouble finding information too, and recently I ran into the problem of finding free sample essays. I visited many student portals, but all of these sites had some free examples or paid access to the sample essay database. I was only able to find what I needed here https://studentshare.org/ , and besides, here everyone can find free tools that really help students with their college or university writing assignments, for example, here you can find a thesis generator for an argumentative or comparative essay.