If you want the best graphics, play with the settings options. Keep everything on "High". I would advise to keep Shadows on Medium, unless you really have good specs.  Playing on massive maps with high graphics settings is a good way to play the slide shows game, at least.   

Okay thanks, and is there a way to make the graphics better?

An advice: don't be fooled by the ELO rating numbers. These numbers mean nothing; some players have unrealistically high or low numbers that will confuse balancing attempts. Since DoctorOrgans has an even chance against me in 1v1 (on Mainland standard settings), you should pretend that he is me when you are balancing teams. That will lead to better quality games and greater probability of completing the challenge.  DoctorOrgans ≈ Ricci-Curvature (1610) Furthermore, placing him with his 'mascottes' will give him a performance boost (nababu).   Something needs to be changed about the rating system, because right now it's totally uncorrelated with skill level. There are 1500s who can roll 1800+ rated players, then there are 1600 players who constantly fail against 1300 rated players. Some 1400 players are very strong teammates whereas others are Petra level. 

The mod is still alive and being developped on Gitea by  @real_tabasco_sauce and others.

The biggest maps are giant maps. There is currently no bigger maps in 0 A.D. Keep in mind that performance degrades depending on the map size. The bigger the map, the heavier it will be on your hardware.

yes

the most popular are all essential things needed to unlock more.