Print not sticking to bed
Often this is caused by contamination on the bed. Wash it well with soap and water, dry it with a clean cloth, and avoid touching it with your hands.
A special glue stick called "Magigoo" is located right next to the printer. If you're still having trouble, apply a thin layer of the glue to the print bed surface (follow this guide). You only need to put glue in places where your model will actually be printed.
Isopropyl alcohol with a clean paper towel can also help, but soap and water are better. There should be a microfiber cloth and a bottle of alcohol next to the printer that you can use.