I bought a bonsai and now?

Question: I bought a bonsai and now?

Today I bought a bonsai at Leroy Merlin. I bought it to put it in my new little office, on the desk, because I love these zen / Japanese style things, the minimalist style and the East in general.
I have never had a bonsai and I have no idea how to treat it. I honestly don't remember the name of the bonsai I bought and since I left it in the office (now I'm at home) I can't see it.
My question is: what do you generally have to do after buying a bonsai? Are there any operations I need to do right away? for example. should it be poured into a larger vase or something or is it ready to put it as it is on a desk?
It is about 20 cm high, the vase is made of glazed ceramic (at least on the outside, inside I didn't notice), or something like that, let's say those classic bonsai pots, dark blue color. The vase is about 20 cm wide.
The land currently seems to me dry, compact. I have noticed that the trunk of the tree together with the adjacent soil moves a little with respect to the rest of the earth (practically there is a bit of earth attached to the trunk that if I move the trunk moves with respect to the rest of the earth in the vessel, as if it were detached). Most of them were the ones that sold. Is it a problem? I have to do something ?
Thanks so much!

Answer: I bought a bonsai and now?

Dear Marco,
usually the bonsai that are sold in hobby shops are plants prepared in series, often of medium or low quality; this does not mean that it is a plant that is not very harmonious or certainly of poor quality, but to have small bonsai at reasonable prices, obviously on something it is necessary to save.
Usually they are plants that already have minute leaves, and therefore it could be a fairly young plant, and not an old bonsai, like those of collectors.
The things we tend to spend less on are the pot and the soil; if you like the pot, I think you can keep it, since usually these bonsai are already in containers of the right dimensions.
The soil, as you say, is instead the sore point: remaining in a compact and poorly drained soil these plants are destined to suffer.
In fact, usually when you buy a bonsai in a non-specialized shop, the first thing to do is to repot the plant, even if you find yourself in the wrong season for repotting; go to a nursery and buy good quality akadama and universal soil; unless you know a trusted nursery and where they deal with bonsai, be wary of molds ready for bonsai, which often contain mixes that are not suitable for these plants.
Take your plant out of the small vase, and gently try to free the roots from the compact soil that covers them; if this operation is difficult, and you risk ruining the root part, try immersing the plant in a basin of water, to try to soften the earthen bread.
Once the plant is released, you can put a thin layer of akadama into the pot, on which you will place the roots and the small plant, which you will then cover with a mix of akadama (about 70% of the final soil) and universal soil. Not knowing what plant it is, this is a mix that works a bit with all the most common bonsai.
Cover the roots well, and lightly compact the soil with your fingers; in the end the plant must be placed at the same depth to which it was previously; don't worry if the vase will seem tiny, you can form a sort of small hill above the vase with the earth and the plant.
Water the plant, possibly by immersion; or prepare a bowl in which you will place the jar, then put water up to the top edge of the jar, and let it soak until you see all the wet soil, drain it and place the plant in its place.
I advise you to write down the name of the plant, and to do some research to understand how much moisture, light and watering it needs.