Well, for free accommodation you can try Couchsurfing. And if your hosts are good enough or you make friends, i guess you can get free trasnport too. But if you are comfortable with public transport or like walking, you can save a lot of cash by exploring the cities all by yourself :)
Do you speak English and have some certification backing that? You can try Diverbo they offer room and board in exchange of teaching English, just talking to participants. There are other platforms for exchange programs, internships, volunteering etc Check this article
https://en.softonic.com/solutions/similar/workaway
Can you please explain your question. Once you've schengen visa you can travel to most of the parts in europe (schengen areas) and better take coaches than flights they are cheap, stay in hostels or become a pet keeper which allows you free stay to people's house and all you have to do is to take care of the elderly people. this way it can be really cheap. Not sure about free though.
Actually I'm looking for free accommodation and free transport in schengen area. I know its impossible to get a free flight tickets. But, free local transport can be possible to reach your destination in schengen area is possible.