I had a short look into your account and found your Lefside Creatives Logo that you uploaded to sell. So let me give you that advice:
If you want to sell Merch of your Brand, than you should create a shop. You can easily click on the plus-symbol on the left sidenavigation of your Partnerarea and create a shop.
Currently you added your design to our marketplace but merch and brnadstuff wont be accepted on our marketplace as for merch - as I said - shop is the right Point of sale.
But if you want to sell designs on the marketplace, then try to research for some niche topics, do also a research if this topic is already well covered or not on our marketplace. If not - then you should go for it.
Of course you could also create designs for evergreen topics like birthday, cats, dogs and so on, but as there are tons of designs an designers trying to get a piece of the cake, it will be almost impossible to generate sales on those topics.
If you want to know more about the difference between the two point of sales (shop and marketplace) just let me know.
Otherwise - I wish you a great weekend.