Web pages that talk about visas for Austria tend to tell me how to get the type of visa they assume I want (or tell me I don't need one). Even the most detailed I found didn't have an option that suited me. I'm not looking for a long time, but more than ninety days.
One legal option I could figure out was to go as a visa-exempt tourist, and learn enough German (A1 level) to apply for a settlement permit before my ninety days expire. But the settlement permit requires spending at least 183 days in country.
What other legal options are available that don't require a job, an expensive school, a lease or purchase on a dwelling, a sponsor, Austria ancestors, or more than six months? I do have more than enough income for the residence permit.
I know that currently COVID complicates things, but assume I am not blocked by that (which is true as far as I know).
Please don't waste words recommending some illegal method, not even if there's zero chance of getting caught.