For maps, I either try to find something online that is similar to what I have mind, or just hand-draw, scan, and then touch up. Gimp and Inkarnate are good tools for this. Some people like to use Affinity.
To design individual rooms and dwellings I use a free tool called roomsketcher. You can get it here: https://www.roomsketcher.com/interior-d ... -software/
. There are others though. Here's a list: https://fixthephoto.com/best-free-floor ... tware.html
For creating clips from YouTube videos I use Veed (veed.io), but again, there are others.