You may be coming into StarCraft 2 (multiplayer) as an experience player who has seen a lot in other games. However, you have to understand that the challenges which you will encounter in this game are scary and daunting. Things are likely to take place at a pace which is faster. It could be the built that you must have chosen to make use of, having it (the build) implemented and fending off or attacking of other forces at once. There are things that you should be aware of before playing this game even though you will acquire most of your skills through firsthand experience.