Your best solution is to contact a Cooperative Extension 4-H agent and find out whether there is a project group for horses in the county in which you live. If there is, you can consider joining the group. The group will frequently exchange knowledge, share ideas, and schedule fun activities for individuals with similar interests. Some groups have members without horses; other groups have members with horses and may plan riding activities as well as educational activities.
If there isn't a project group that you are interested in, you could consider starting a project group. There are likely to be other individuals enrolled in the same project who would also like to know more. This is something that you can ask your 4-H agent to help you with.