Unless my memory is failing me, I seem to remember being told about Godan and Ichidan verbs, but some words are just listed as する verbs. How do they vary from the others, and what conjugation rules do they follow?
する is special verb that is used to translate English verbs like “do,” “make,” “take,” etc. It is transitive, which means that it takes a noun as an object. For example, take a walk is 散歩をする.
A する-verb is a verb constructed from する and its object. For example, 散歩する. It means the same thing as 散歩をする, but now it is an intransitive verb instead of a verb phrase.
する-verbs conjugate just like する does. As previously mentioned, する is a special (irregular) verb, neither ichidan nor godan. You can see the full conjugation table by clicking on the part-of-speech label in its dictionary entry. Note that this table includes many conjunctions that you probably haven’t encountered yet and don’t need to worry about now.
Almost any noun can be made into a する-verb. Only the most frequently used will have dictionary entries.