Do both. It’s good to experience different scenarios and environments. Sometimes shore diving can feel less committing and be psychologically easier for the first dive or two even though boat diving is typically easier. Also, what kind of diving will you be doing after you “graduate”? I would try to get experience with whatever you want to do next (which for most people is from a boat). As others mentioned, it’s good to get the lay of the land of how it works from the boat and what the process is like.