Can you please give me advice or idea?

[Jecterra]

Hello everyone, I have been following this forum as a guest for a long time, but I decided to register now as I am seeking advice. I am from Bosnia, which I think is important to mention for this topic.

My family member is involved in the printing, embroidery, and manufacture of apparel such as shirts and hoodies for many years. He has some regular customers and is satisfied with his current workload, but he has given me the green light to start something new and expand the business.

I have many ideas, such as creating t-shirts, canvas paintings, hoodies, and more. I am not sure what topic to focus on, whether it be sports, movies, music, or a combination of everything. I am also considering whether to start a new Instagram/Facebook page or purchase one with lots of followers.

I have been thinking about this for a few months now, and I am still at the beginning. If anyone has a smart idea or a business proposal, I would love to hear it. Thank you in advance!