Try asking yourself - where does my target customer hang out? If your product is targeting professional business people, then LinkedIn would be a good place to start. But if your customers are consumers and predominantly female aged 14 - 25, perhaps TikTok would be better. Older consumers of both sexes are more likely to be on Facebook, so that's also a good place. If you want to sell to elderly consumers, there may be no best place!
Let me know if you'd like to chat further.