A1-  

You’ll need to get a copy of MCEdit to import from Tinkercad to Minecraft. There’s a tutorial and more information here: https://www.tinkercad.com/minecraft 

Look for “Tinkercad & Minecraft?”

A2-  

Here are a couple tutorials.

Tinkercraft!

A3-

You’ll need a “go-between” piece of software called “MCEdit” to do this. Here’s a link to a good how-to article from Tinkercad. It’s based on the older version of the Tinkercad, not the current beta release, but it still helpful.

Tinkercraft!

A4-

I’m willing to work with someone to train.  If they haven’t found it online as of yet.