一応 + [sentence]
一応 is an adverb meaning "just in case", "to be on the safe side": you do something that may turn out to be unnecessary. It usually opens the sentence or sits just before the verb, and it goes naturally with ておく.
About a result or an ability, 一応 says it meets the minimum and no more. Said about yourself, it is modest: "don't expect too much".
These go beyond "just in case" and "more or less".
With a plan or an arrangement, 一応 marks it as provisional: it may change.
With a title or a role, 一応 says it is true on paper, and often that the reality is different.