Many schools and workplaces use web filters to block gaming sites (like CrazyGames, Poki, or the official Paper.io domain). “Unblocked” versions are copies of the game hosted on alternative domains or embedded in proxy-friendly sites that bypass these restrictions.
If you are feeling bold, look for opponents who are outside their own territory trying to capture huge areas. If you can cut off their trail before they reconnect to their base, they explode, and you can swoop in to take all the land they just captured.
New players often make the mistake of overextending. Start by taking small chunks of land directly adjacent to your base. Never stray far from the safety of your territory. It’s slow, but it guarantees you aren't an easy target.