The 3D drawing package is just the basic Google 'Sketchup'. i don't need some of the more complex functions of Autocad so managed to get buy with Sketchup and saved having to renew my Autocad licence
Google Sketchup - > https://www.sketchup.com/
The printer is a cheap and cheerful 'Wanhao i3', there are many versions of this, and they're all very much cheaper now than a year ago (under £150 new) I think the one I have is a clone of a 'Prusa i3'.
My workflow consists of design the piece in Sketchup and expor ther file to 'STL' format. Then import that file into 'Cura' (which comes with the printer), which 'slices' the model into discrete layers for printing. The output file is 'GCODE' format which includes various printer specific instructions (temperatures and speeds) as well as the model, which is saved to an SD card. The SD card is inserted into the 3d printer control box, and the print is started.
The most critical thing as far as the printer is concerned is that it is leveled properly, and that the gantry is perfectly perpendicular to the build plane. This takes a few adjustment sessions to get into the ballpark. Then the most critical part of printing is getting the first build layer to stick to the build plate. I'm using a gluestick rubbed on the plate for that, like may people use, but you can also use hairspray. Some people fit a glass plate to the build plate to ensure flatness. My build plate is fitted with an optional heated plate surface which also helps with adhesion.
Once you have found a setup which works it is best to start printing and keep going, because some small tweaks are required from day to day with this model as the dimensions of the frame change slightly with temperature....but like anything else this is the way life is at the bottom end of the market.