Could anyone please give some advice regarding the original questions?
Here is a link to the developer of the game (splash damage) website. There you can download the full game, as for the MP, you might need to do something special, i would ask this question on their forums that they have a link to on the page as well.
www.splashdamage.com
As for the CSGO problem, i dont know what to tell you. They had it seperated between Competitive and non-competitive modes. If youre looking for a match with real people, youd go under competitive, im not sure what the set up is like now though because i havent played it in a while.