There's probably a typo or an error somewhere along the line.
Cursus is a 4th declension masculine noun. Cursuum (with 2 u's) is a genitive plural - that would translate to 'of the courses'. Cursum (single u) is the accusative singular. That's what would be used as the direct object of a verb.
I suspect it's supposed to be 'Cursum Perficio', Which would translate to 'I finish the course.'
"I am doing a course" is one possibility.
But it depends on the context. Cursus can meanrunning; speed/zeal; charge, onrush; forward movement/march; revolution (wheel),course/direction, line of advance, orbit; voyage/passage; race; career; series;