Peeing outside his litter box is not indicative of anger. What behaviors are making you think he’s mad at you? What makes you think he has attitude problems?
For litter training, confine him to his pen until his habits improve. You have to start small as too much freedom/space too soon can invite litter habit issues. He will pick his favorite spot to go to the bathroom and that’s where his litter box should go. Some rabbits need multiple litter boxes during training. Put some hay in the litter boxes/generally make them a pleasant place to be. It’s okay if he hangs out in there and spending time in his box will encourage good litter habits. Soak up any accidents with a paper towel and place them and any stray poo in the box. This also encourages good habits. Clean up any accidents ASAP with vinegar, baking soda, or some other animal safe cleaner. Any residual smell of urine will cause him to keep having an accident in the same spot.
You can find very detailed info about litter box training on the web sites that Sarita and I linked on your other post. So I would give them a read if you haven’t.
He’s only been with you 2-3 days so be consistent and give him time. He’s still adjusting to his surroundings and this is normal for a new bunny. If you want to double check to see if he’s neutered just look and see if he has testicles. If he has them he’s still intact.