OLL or Orientation of the Last Layer is the third step of the CFOP method, which aims to orient (same color facing up) the top layer of the 3x3. This step is fully algorithmic, and consists of 57 cases.
Two look OLL is a smaller subset which orients the top layer in two stages. First, the edges are oriented - There are 3 possible cases. Then the corners are oriented - There are 7 possible cases.
It is easier to memorize algorithms using "triggers", which are short and reoccuring sequences of moves.
The most common ones are:
Most algorithms begin by taking one pair out (often front-right or front-left), doing something with it and then putting it back. to memorise the entire alg more easily, try following what is happening to that pair.