If you are wanting a calmer rabbit, breed can only get you so far. There can be a fair bit of variety in many breeds. Holland Lops can be calm, but they can also be crazy. You may want to look for an adult rabbit so you can see more of the personality compared to a baby. It can also be easier to see how a rabbit fits the breed standard when they are more mature. Even 6 months can be a good age to see what a rabbit is like as an adult.
Since you are thinking about breeding, you should get a rabbit that would be good for breeding, even if you don't end up breeding. A good breeder can help you get one that could be more suitable for breeding.
Start small. Maybe get a rabbit that is easier to handle for showmanship, but show both rabbits in open or youth shows. This can help give you some more experience in the show world. If you find you like showing, then breeding can be a good next step. Getting involved with breeders can be good to see what breeding is like. If a breeder lives pretty close to you, you might be able to help them out and get more hands on.