We gave away 5 Creality Ender-3 3D printers. These machines are under $200 and make very impressive prints.
7 upgrades you can print for your Ender-3
7 more upgrades you can print for your Ender-3
Bed leveling video - in case you need more info
If you are having bad print quality - how to troubleshoot :-
Don't forget to add Octoprint (on a Raspberry Pi) to put your printer on your wi-fi network and capture time lapse videos. No more copying gcode to SD cards, just drag and drop in a browser.
It has hundreds of plug-ins to expand what Octoprint will do.
This guy has a discussion of getting better looking time lapse videos https://www.youtube.com/watch?v=SvZjNSLXAJc
A place with LOADS of models to download and print
(Search and have fun - I suggest star wars to begin with)
Create a use account and add them to your list. As an hour or so on this site, and you'll have LOADS of ideas....
Download the latest Cura slicer (Currently V3.6 as of writing)
Pick "Ender-3" under "Other" when configuring for the first time.
This will "slice" your STL model (as downloaded from Thingiverse) and produce gcode which is what your printer understands.
As you get more experience, you can tweak slicer settings to try things out, but the basic default is good to start with.
Lots of info on 3D printing on YouTube. I recommend TeachingTech
and 3D printing Nerd
You can lose hours and hours of time in to this, always new things to learn. But 3D printers are at Apple 2 days - ie they have a very bright future ahead of them and knowing all about them has to be good.
Eventually you'll want to build you own models. I use Fusion 360. Works on Mac/Windows.
You can get a makers license for free. You just need to renew it each year.
This guy does excellent videos https://www.youtube.com/watch?v=A5bc9c3S12g
Thats enough to keep you busy in 2019... and maybe 2020.