Starcraft – Playing as Random on SC2 matches will unlock Racial portraits too

I may be mistaken, but I think the change in fog-of-war is one of the changes between Starcraft 2 and Broodwars. The idea is that the map is no longer unknown (as that benefits users who spent the time memorizing maps from their starting locations).

Play the other races.

Sure, you might be able to advance your score faster by focusing on one build, but you're also a lot more likely to become bored. At the bronze level, the most important lessons you can learn are transferable between races, like building workers (build a lot, and keep building), building buildings, expanding, and keeping pressure up.

If you feel that this is too hard, or playing all 3 races is too much, then I recommend you focus on either the zerg or protoss and terran. Z plays very differently from P/T and you might run into frustration if you try to play Z the same way as you play P/T.