Generally, skill yourself for a career with high future demand that can be done remote, like DevOps, Data Analyst or Sharepoint Admin.
Then get hired by a company that pays well and live in an area with low cost of living.

Or like me, have a fuckton of luck, and happen upon a hippie landlord who inherited a house on a large woodland plot and lets you rent it for 500€ as long as you do all the work that needs doing and don't bother her while she finds her true inner spirit 500 miles away in the Alps.
Then heat your home with firewood from your own plot, build your own furniture in your shed, grow your own veggies, join local food sharing and fleamarket groups, live car-free, go on camping trips for vacation and bring your cost of living down to a point where 40k€/year are plenty.