G'morning countrykid......Good to hear that you are making progress with your Echo Dot.
I must admit that I don't have such a device but, from time to time, I read about such items. In fact I thought that Amazon had corrected the matter of 'fake wakes', but that does not appear to be the case. It seems that anyone saying "Alexa" can wake her; even if the name or similar (Alex Alexis) is heard from a radio. Consequently, you will need to set things differently, if the issue is causing you concern.
There are lots of articles on the Internet which are helpful and the following is one of them:-
https://www.digitaltrends.com/
Incidentally,as regards adding Alexa to other rooms, it will mean getting further Echo Dots
Best wishes .....Hans.