Problems with the modes and servers (Garry's Mod)

Not so long ago, I decided to buy garrys mod(the game not the pirates), while as the first time I ran it next to me stood my friend who also has gm(and it had dramatic to say the least, not a few hours), and as soon as I launched it it told me that I have very few modes (he gave the example of the flood mode, which I do in the game for some reason was not, that is the many popular modes simply did not exist in the list), once said, that servers for each mode, is also very small. Please, who knows what is the reason, tell me!!!