For X-Plane 11, there isn't a high-fidelity "study-level" Boeing 787 that is completely free, but you can download several freeware "lightweight" models or find a paid version that is widely considered the community standard. Freeware Boeing 787 Options
(airline paint schemes) for these models. Boeing 787 X Plane 11 Free Download
If you have purchased or downloaded a legitimate aircraft file, here is how to install it: For X-Plane 11, there isn't a high-fidelity "study-level"
A strong competitor to FlightFactor, favored by some for its newer technology base. For X-Plane 11