A small selection of the resources available to learn about the various software packages that make up the 3D printing workflow. There are other resources available at Thingiverse : Education
The TinkerCAD website has several good tutorials, and there are a wealth of good videos on YouTube.
FreeCAD is a large Open Source 3d Parametric Modeling suite. It's scope is similar to Fusion 360. There is even a wiki on Migrating from Fusion360 to FreeCAD The software is organized into workbenches containing tools set up to for specific modeling tasks. There are a variety of included workbenches and several others available. FreeCAD is scriptable in python and scripts can access just about any of the functionality of the workbenches and can also run standalone to provide custom workflows.
Meshmixer is a tool for editing and repairing 3D triangle meshes such as you get from 3D scanners or models not originally designed for 3D printing. It can also simplify models, shrinking the .stl files and making slicing faster.
Slicers are used to convert .stl files into g-code for the printer. You can create sets of custom settings for your specific printer called a profile.
There is endless information available on the Simplify3D site. Like many other packages the Simplify3D folks also have a YouTube channel.
Used to send designs to a directly connected printer. Provides a way to control printer directly, setting temperature, fans, homing the axis. Loads g-code files into the printer and monitors the progress of prints.
It's somewhat hard to separate the MatterContol tutorials into Modeling, Slicing or Monitoring as most tutorials cover all three.
OctoPrint provides a web accessable interface to your printer. It is popular to install the OctoPrint monitoring software on a RaspberryPi called OctoPi. There are lots of helpful people on the OctoPrint Community Forums. Several slicing programs have OctoPrint integration built in.
Some videos and tips on how to solder, from thru hole components to surface mount. I suggest watching all the basic ones first and then getting a soldering iron/station and trying things out, before diving in to the more advanced ones. There are some cheap kits for learning to solder at the MakerShed
A better overview of the tools and materials as well as info on working with SMD (surface mount components) and some more advanced stuff (Dave is a bit opinionated, take with a grain of salt, in light of the above videos)
You can print threads on FDM printers, with some limitations as to how fine the threads are. Resin and SLS printers can do a much better job with fine threads, but there are limitations as to how the threads are oriented. On FDM printers, thread designs like screw top containers and coarse threads (think soda bottle tops) are most appropriate. Talking about internal threads for designs that need fine threads there are three options; use a tap & die set to cut threads into the printed part, use a metal threaded insert, or use an embedded nut.
A threaded insert is best when you need strength (or if you don’t have a tap & die set), at the cost of a bit of space around the threaded hole. The inserts can add several millimeters to the hole diameter. They are installed by heating the metal insert (usually using a soldering iron) and pressing it into the properly sized hole so it melts its way into the part.
Tapping a hole uses a cutting tool to carve threads into the plastic. It works best with tough and stiff materials. You still need to leave a bit of space around the hole but not as much as for the threaded insert. You will need to make sure that there is enough plastic for the tool to cut into, possibly by increasing the number of horizontal shells around the hole in your slicer.
Designing in a "pocket" where you can insert/embed a nut is a popular technique. Care needs to be taken to make the pocket tight enough so that the nut cannot rotate in place. You can see examples of this construction on the Prusa M3 and other printers.
There is another method that may not really belong in this list, using self-tapping screws. They still need a pilot hole and want some extra space for their threads to bite into the plastic, but they may be a good alternative.
Since FreeCAD also incorporates OpenSCAD, the info for OpenSCAD may be relavant