What is the most logical next event?

How to convert the garage into a private study
Clean out the garage.
Remove everything and make a decision on whether or not you need to keep it. For the items that you keep, you will need to make a decision about where these will go.
Do you have a garden shed, or perhaps the items can go in the basement? Alternately, the garage items can remain in the garage but purchase or build better storage facilities that hide the items away from site. Lay garage carpet on the entire garage floor.