Any business that doesn’t require a large monetary investment or the investment is small enough that you won’t have to take on debt just to get started. Most businesses that fit this criterion are online businesses like selling digital templates, online courses, and affiliate marketing.
Alternatively, you might start a business by utilizing your skills like writing, or editing, because they don’t require any upfront cost. Also, starting a YouTube channel or becoming a social media influencer as you can do most filming and editing with your phone without needing to invest in professional equipment.