You can learn solidworks just by playing around with the software. Its that easy. As with any CAD software, it's your familiarity with it that determines how fast you can create the geometry you want.
And it's a very useful skill to pick up. Some of us have used it to design custom adaptors for different tracking mounts. Coupled with a 'universal' pier system also of our own design, we can really save money in the long run.
It is very hard to get the demo version of this software you need to get the license from the local agent which can take a while unless you are from local university. I will suggest you try Solid edge or Autodesk Inventor, those you can just download the 45 days or 30 days trail verison online from their respective website.
Essential, those software have very similar work flow and functions. My personal favourite is solid edge. Start off by modelling the parts than merge parts into assembly. No a hard software to master and learn however the price tag on those software are far too expansive for the common people.