Independent learning may but doesn't have to be solitary. There are times when it's easier to work entirely independently without having to coordinate with someone else, but there are other times when it's useful to discuss your thinking, discoveries, and difficulties with someone else who shares your interest.
Usually, culture refers to areas that are also called the fine arts. I use a much broader definition in the classification of knowledge I use. The three major categories are
Ideas include language, literature, graphic arts, mathematics, applied science, and philosophy. Behavior includes customs, occupations and hobbies, sports and games, performing arts, and special events. Objects include foodstuffs; clothing and dress; buildings, furniture and structures; vessels and vehicles; communication media and devices; tools and machinery; and other miscellaneous artifacts. These are overlapping categories, and many other possible classifications can be made.
These are more closely related to nature and natural science than the other areas discussed. They are rooted in the needs of individuals and are products of human activity, either individually or in groups. These are also closely connected to the institutions of family, education, economics, government, and religion, and different communities, cultures, or peoples have different varieties and forms of culture. Each of these areas has a history, and the historical development of culture, and elments of culture is an important part of study. Experts in any particular area, whether it is painting, stamp collecting, or military aircraft, become familiar with the history of that area.
Because this is such a broad subject, the only thing I recommend is to make a list of your particular interests and activities, and things you would like to learn about. I intend to return to these subjects with more specific suggestions.