Translation:I go on walks.
It's not ambiguous. They just don't tell you that there are different verb sets. One must take a subject like 'I' or 'she' etc. The other can not take a direct object sometimes they can't take a subject. These sets are called transitive/intransitive verbs. We have them in English, only the forms of transitive verbs are the same as intransitive verbs so no one notices. Suru is always a transitive verb so it has to have a subject. If a subject isnt presented already one must assume that the subject is 'I', the speaker.