Ok, so my problem have been sloved. I did find out how to run Second Life on my Linux Mint 13 Maya OS after like a hour when I crated this thread. I read the first few replies, what didn't really helped much, just kinda discovered it by accident by myself. I prolly should do this earlier, to inform you, but I will tell you NOW what I did...
So basically all what was needed is to extract the dowloaded file (SecondLife-i686-3.3.1.254524.tar.bz2 (I extracted it in Downloads folder and run the game from there too)), open extracted file folder, find the file in it named "secondlife", double click it and press "Run in Terminal". That's it, no instaletion was needed. ^^
Thank you very much to everybody who replied to this thread with helpful information. ^^