Okay, so OLL is the step where you get all of your top center color on top. For instance, say you have yellow on top: By funding the certain OLL algorithm that matches all the yellow stickers in the top layer, you will be able to get all the yellow stickers facing up. There are 57 Full-OLL algorithms, however I suggest you learn 2-look OLL first, as you only need to know less than ten algorithms.
PLL is the process of taking those pieces that are yellow on top and swapping them (being certain edges for other edges, and/or certain corners for other corners). These are recognized by color patterns, and OLL cases are recognized by strictly seeing where all the yellow stickers are placed. There are 21 PLL cases, and each is named after a letter of the alphabet.
Let me know if you need that to be better explained
The best way to learn those both PLL and OLL algorithms is to look for certain triggers. You might of seen the letters R U R' U' before. That is a very common trigger, and people call it the sexy move, or just sexy. Another popular one is called a sledgehammer (or sledge), and in letters it looks like R' F R F'. One great example of an OLL case that uses both is
this OLL case. As you can see, it is shaped like a T, and it has two edges and two corners facing the sides. The way you solve it is by doing R U R' U' (or sexy), then R' F R F' (or sledgehammer), and by knowing the names of the triggers, you can abbreviate it as "sexy-sledge!"
Another way to learn algorithms is to remember this: A lot of OLL and PLL cases take out an F2L pair, and put it back in a different way. If you follow the pair, you will be able to connect the F2L movement with the case, and execute it (if that makes sense).
Let me know if you have anymore questions!
