I am also not a veteran, but based on my limited knowledge, maybe I can put it this way:
Type I -- Conquest Type victory
This is what you and most people are trying to do in every game. This type of victory focuses on being the top scoerer, usually with the largest land and the most income. When you get more experienced, you can advance faster and make harder difficulties, so you get higher scores. On most map types you will achieve a domination victory before a conquest.
If you can't achieve domination because you didn't advance fast enough, you usually end up with a space ship launch (technology victory).
If you can't achieve tech victory fast enough because your economy isn't strong enough to research all the space ship parts before the turn limit, you get the time victory (just being the top scorer).
Type II -- Diplmoatic Victory
You have to plan ahead and make more friends than anybody else. Finally, you need to win a good majority vote in the United Nation (a world wonder). On higher difficulties this is harder, because AI will find themselves some best friend before they consider you. However, you don't need to be the lead scorer to achieve it - although it certainly helps. (so you can give out free techs to the inferior Civs).
Type III - Cultural Victory
You need to completely abandon research and turn your cultural bar to 100% halfway through the game. Finally you will have enough leading cultural cities to meet the victory condition. If you are a powerful Civ, then you should be able to pursue this victory. Otherwise this is pretty much suicide.
Personally I have only tried the Conquest Type... but I am sure that the other two types are certainlly fun to try.