you can print the name of the merchant on it, which is equivalent to playing the role of a trademark. However, unregistered trademarks are not protected by law, and others can also play like that on their own goods.

you are a self-employed, not a company, so you can't use the word "company".

Supplement:

There is a difference between a trademark and a registered trademark.

you can call the manufacturer yourself or the OEM. This will have a certain impact on after-sales service and brand building. It also depends on how the product quality responsibility is stipulated in your processing contract.

If the OEM is a company, even if they are responsible for product quality, they are limited. As a self-employed, if you are responsible for product quality, you are unlimited.