I installed DF a year ago but got frustrated with a few issues, so uninstalled it. I'm now ready to give it another try so consider me a "new user".

I go to W10 settings and choose "extend these displays" and my main monitor always is identified as 2. How do I get my main monitor to be 1 and my second (right side) monitor as 2?

Also, I can only get my mouse to travel to my second monitor by moving it to the extreme upper right of my main monitor screen. Is it possible to simply drag the cursor to anywhere at the right to get it onto the right monitor, then back to the left to get to the left monitor?

"I go to W10 settings and choose "extend these displays" and my main monitor always is identified as 2. How do I get my main monitor to be 1 and my second (right side) monitor as 2?"

Swap the connections into the graphic card ports around, that should sort out the monitor id numbers although its not that important what id number they have.

"Also, I can only get my mouse to travel to my second monitor by moving it to the extreme upper right of my main monitor screen. Is it possible to simply drag the cursor to anywhere at the right to get it onto the right monitor, then back to the left to get to the left monitor?"

On your desktop right click and select Monitor Settings (I think thats what its called in English), you will see the monitors you have connected.
Click and drag the monitor on the right over to the left hand side of the other monitor, so in effect swapping them around and your mouse should travel between the monitors properly.