Do you like to make a lot of jokes? Are you often silly? Are you usually happy? If so, then you are a jocular person.
Being jocular has to do with being both jokey and fun. A jocular suggestion is not a serious suggestion — it's a joke. Some people are more jocular than others: anyone who is ultra-serious and always frowning is not jocular. A comedian makes a job of being jocular. Class clowns can't stop being jocular, though the teacher might just see them as obnoxious. Being jocular is usually considered a good thing: it's not just about making a lot of jokes; it's about being happy and pleasant to be around.