Rein here from Shopify. It's great to see that you are making sales and looking to grow.
There are plenty of strategies to finding profitable products. What I have seen work a lot in the past is to start with a problem (for example your dishes are not drying quick enough in your kitchen) so you look for solutions and build your store around that.
There are plenty of other ways to tackle this step though. I would high recommend you check out this blog post for more information. It has a total of 12 different strategies you can learn and use.
Have you any problems you can think of that you would like to solve that you think a product/service could assist with?