First Layer

Most problems that people have with a print can be traced back to the first layer. If you do not have a good foundation, whatever you build on it will have problems

Clean the bed.

Level the bed.

This reddit has a wonderful WIKI that goes over many problems and how to fix them. https://www.reddit.com/r/3DPrinting/wiki/troubleshootingandcalibration/ 

For a print the file must include code to generate/use a mesh.