Well, here are some conflicts about Jacob:
1. Bella knew him when they were kids, but now they're all grown up (sort of) and he has a crush on her, which he forms almost immediately upon seeing her at LaPush. She uses that to get information out of him about the Cullens, so she feels conflicted internally over the guilt of using Jacob, and it sort of starts the external conflict between Jacob's and Edward's affections for Bella.
2. Jacob wasn't supposed to tell the secret about the "cold ones" and the members of his tribe. But he did it anyway, to impress Bella. So that kind of puts him in conflict with his tribe/tribal traditions.
3. Jacob gets into the middle of the conflict between Billy and Bella when he agrees to go to Bella's prom to warn her about Edward.
4. Beginning in Twilight but mostly in the later books, Jacob is like a walking conflict between his loyalty to his tribal heritage and his modern and personal desires. This is evident by his love of motorcycles and fast cars, his torn emotions about the pack, and his ties to the Cullen family.
So here are two internal conflicts and two external conflicts regarding Jacob.
1. There is always a tug between the feelings that Bella has Jacob and Edward. She's constantly in this state of "should I leave or should I go". Because of this it leaves Bella in this state of guilt.
2. Also Bella feels a sense of duty to be the friend to Jacob the way he was for her when Edward broke up with her. Now that she can't fulfill this it's almost like she's worthless to him.
1. Bella also has to keep both sides vampire and wolf, Edward and Jacob apart from each other because of the constant tension that arises between them.
2. Jacob is also responsible for getting Bella in more trouble than she already was when she came back from Italy. Jacob told Charlie how Bella was riding motorcycles and jumping off cliffs.