facebook, instagram or something else...slightly confused as to the best platform to use?

I have a new personalised range of items I'm soon to be selling, but it's been quite a difficult process to make and due to the small amount I will be selling at any 1 time (maybe 15) I just wonder what platforms are most suitable to market and sell through. I have a factory that makes part of the item and it takes them approx 7-10 days to send out about 15 items hence why I try to to order larger quantities as it can take far more time. When I receive the items back, I then use these to complete the finished piece which takes additional time. I originally was going to sell through my ebay shop but with no marketing and only max 15 for sale say every 2-3 weeks I wondered wether Instragram or facebook may be better. I have never used facebook and don't understand how to set up a business page then get followers. I have an instragram personal account only and constantly see products being sold through it. I've used etsy on a previous venture and found it slow but does appear good for personalised items. Ebay on the other hand has always been my primary business but I've seen a massive slowdown in recent years and often find people are only searching for regular items/brands using keywords, but anything that might be new & unique is that much harder to sell unless there is sufficient marketing behind it.



I just wondered on what people thoughts might be when selling items with no marketing and in small quantities.