Your Boss is realizing the the future is digital manufacturing.
Bless his heart for giving such modern tools to work with.
Some bosses / companies will fund higher learning for their employees.
Company I worked for provided a loaner computer and paid my tuition for a local software class.
Computer modeling is very helpful skill set to have that improved my earning power.
Jump in ... the water is fine.

So when looking at software to use examine what file formats it can import and export. What plug ins are available etc.
A user interface that is easy understandable is nice.
For me Sketch up was easy to learn but the path to a useable .stl export was difficult. It did set the path for me to learning other software.
123D and Tinkercad are simple and export good .stl's
Try everything you can your hands on