This could indeed be Cypress, or maybe more likely Juniperus.
I am growing for over ten years bonsai now (with ups and downs), and I certainly don't want to call myself an expert but I think I can share some tips I have learned along the way.
First tip is to find material in your own neighborhood. For example, I live in Amsterdam (Netherlands), and in the city I can find often some rough wild (neglected) places where I find young tree saplings. Also you can collect seeds. This way you know for sure that you have trees that will do well in your climate. Last year, for example, I collected seeds from cones from Scots Pines and have them growing as saplings now. Moreover, it is for free, you don't have to order from internet (with sloppy sellers, that don't even know the difference between pine and cypress or juniperus).
Second advice is to grow seedling first a few years in normal containers (and repot in larger ones when necessary). I have an Italian Cypress grown from seed (seeds collected in France from the garden of my parents), and had it grown in normal containers for 6 years first. The trunk will grow quickly thicker this way, the way you are now growing it (immediately in bonsai pot), will take many years before it will have a thick trunk. Probably 10 to 20 years.
Last tip is to grow bonsai outdoors. Indoor bonsai is only possible with some tropical species, but even then it is very hard to keep them alive for long.