I recently installed the game, and I have questions

I installed the game via Steam, and I have many questions:

-Why does my settings don't save on servers?
-How do I reduce graphics to improve performance since my computer can barely run it with the constant explosions, gunfire and bullets in matches
- Is it normal that servers download some files before entering a server in the first time?
-Any recommended servers that don't have bots?

My IGN is cryztalyz87 btw, and my timezone is in SEA, so maybe i can barely join populated servers in peak hours