>Your 3D print failed?
https://www.simplify3d.com/support/print-quality-troubleshooting/

>Calibrate your 3D printer.
https://teachingtechyt.github.io/calibration.html

>Where can I get things to print?
https://www.thingiverse.com/
https://thangs.com/
https://printables.com/
https://grabcad.com/
https://www.yeggi.com/
https://cults3d.com/