Are there other legit places besides OLX to find teacher jobs,
Bascially any jobs website will have an education section.
the preschool offers are plenty and I could at least earn 7k - 8k zl per month if not more (or so the offers say).
I presume those are private pre-schools? The pay may not be as much as they say. They sometimes advertise high salaries, especially if they're using a recruitment agency, but the actual offer is lower or if it's from an agency the job doesn't really exist. They just want to register you on their books and that's how they suck you in. Do the jobs mention language skills in Polish?
Another thing to bear in mind if working for private pre-schools is that they are often run by chains on a franchise basis and the owners/principals of the schools have no background in education and make a lot of demands on staff. Expecting you to do a lot of stuff outside of working hours is common.
The only thing I can think of that you may have overlooked is working in art therapy or art for disabled adults or children, maybe in a centre for autism or something.
A lot of jobs in Warsaw are found by word of mouth, through making contacts, so I'd say get out and about and start networking in likely places. You can also go door-to-door with your CV. In Poland a visit in person still works better than emails.
You could also try making contacts through volunteering, though it's not a big field in Poland.
Forgot to mention, a public high school in Poland would require fluent Polish.
