Struggling with my first sell.

Don't struggle. Just make models and upload them. Eventually some model will be sold.
When I uploaded my first model here, I've been thinking that if I sell one model in the next year, it will be motivation for me to continue. In the meantime I was making other models and uploading them...
Don't worry, sales will come.

Hello there,

You have very few items, most of which are from a highly competitive niche (furniture).

Create more sci-fi models in the amount of about 100 items. The more complex your models are, the less they will be required to start selling.
There are no complaints about the quality of the renders and the description, everything is good.

Regards.

Hello. You need to increase your model count. In addition, the furniture category is extremely crowded. If you will continue to make models in the furniture category, maybe you will have a chance with high quality and trendy models. But my advice to you is to install at least 50 models in the first place. At least 50 models belonging to different categories. Then I suggest you find which model and category is the best seller and continue on that category and model type. Keep up the good work.

I still could use some advice?

look for and find models that don't exist yet, then model well, look at other modelers, etc you'll figure it out all by yourself. p.s. open day use by companies and authorities, so there is in Germany (police, army etc)

Enrico