I own a number of trademarks. You can protect a text, name or graphic or any combination. The work is normally done by trademark specialist or lawyer who first performs extensive research to see if an identical or even similar mark already exists. You then pre-register your mark either nationally, or internationally (specifying countries or groups of countries). Following pre-registration you may get into disputes with other companies who believe you are infringing their own mark in some way. There are companies out there dedicated to monitoring pre-registration, then surveying the wider market and alerting other companies or individuals to potential infringement to encourage dispute (which of course they then manage). Disputes can be costly and time consuming, so it's best that the initial research is thorough to avoid them in the first place. One disputes are resolved (or none arise) the mark is formalised, usually for a fixed period, typically 5 or 10 years after which you can renew it reasonably painlessly.
Typical cost of a text/graphic mark protection is 3000-5000 Euros including all research, legal costs and registration formalities.
Once you have a mark you should check regularly to see if anyone may be illegally using it, or something similar - that can turn into a lucrative business

YL6