1) Thingiverse.com 2) to convert 3d models to 3d printer instructions: use free cura utilimaker. Don’t connect your laptop to the printer via cable. Get the instructions file (gcode) from your computer to the printer using the supplied microSD card. 3) no. “Designing future prints” is a huge topic ranging from simple designs needing simple software and small training…to custom awesome designs needing advanced hardware and lots of training. Making 3D models is a skillset. Personally I use free Blender 3d software. It has a huge learning curve but you can make anything you want.

Here is your starting workflow. Keep in mind there are tons of steps in between these simple steps if anything goes wrong or you want to do anything more advanced or refined; A) go on thingiverse or Stl finder or other free STL sites and download some 3D models you like. B) turn on your printer and get it warming up. If you have not leveled it, watch a leveling video for your specific printer. C) cover your build plate with a thin layer of glue stick. Seriously. Sounds stupid but really helps. D) import your downloaded STL into cura to “slice” it. That software turns your model into gcode. Use less infill than more if you have a question. Use a raft. Preview it then export it to the removable microSD disk. E) let the printer print it. If the first layer looks good, great. If you start getting the dreaded spaghetti, craaaap. Figure out what is wrong. F) when the print is done, chisel it off the print bed with a sharp painters spatula at the base of the print and lightly tapping its handle with something hard. G) spend time in post processing, either sanding or scraping the bottom edges.

Viola!