“Now I will tell you the answer to my question. It is this. The Party seeks power entirely for its own sake. We are not interested in the good of others; we are interested solely in power, pure power. What pure power means you will understand presently. We are different from the oligarchies of the past in that we know what we are doing. All the others, even those who resembled ourselves, were cowards and hypocrites. The German Nazis and the Russian Communists came very close to us in their methods, but they never had the courage to recognize their own motives. They pretended, perhaps they even believed, that they had seized power unwillingly and for a limited time, and that just around the corner there lay a paradise where human beings would be free and equal. We are not like that. We know that no one ever seizes power with the intention of relinquishing it. Power is not a means; it is an end. One does not establish a dictatorship in order to safeguard a revolution; one makes the revolution in order to establish the dictatorship. The object of persecution is persecution. The object of torture is torture. The object of power is power. Now you begin to understand me.”
― George Orwell, 1984
Most of the internal conflicts arise from Winston's unhappiness with his life, and his suspicions that it is the Party that is the cause. At the beginning of the novel he is absolutely miserable, and that misery is mostly caused because he hates the Party and feels like he is the only one. He cannot be happy with it--it is an interna, Man vs. Self issue (even though his unhappiness is caused by the Party, Winston is conflicted with his angst about it). He struggles each day to even have motivation to get up in the mornings. He wishes so badly to know more--more people who feel the same, more about the history of the Party, and more about what causes true happiness.
So, internal conflict comes from Winston himself. After he meets Julia, he is conflicted constantly about his paranoia of being caught. It is always there, like a haze over his happiness. He is also internally conflicted about whether or not to make himself known to O'Brien; his fear of being caught battles with his desire to be part of a larger group of rebels.
The external conflict comes from the fear and repression that the party puts on its members. They are constantly watched by Big Brother, which leaves them living in continual fear of punishment for rebellion. They are even afraid to sleep, as their subconscious minds have betrayed them as they were sleeping. The party maintains that external fear through contstant examples of punishment, encouraging others to turn neighbors in, and propaganda.
Other external conflicts come at the end with Winston's torture and the slow deterioration of his body, and accordingly, his mind. The torture techniques appplied are external conflicts, that stem off of his internal fears of losing his mind, losing his love for Julia, and giving in to his worst fears.
I hope that those thoughts help to get you started; good luck!