Hi,

I am confused by the information available here and on the Internet.
Are there any mandatory courses for dog owners in 2020 or not?

I'm relocating to Switzerland in April with my dog which I'm owner of for 2 years.
In case that matters we will live in canton of Aargau for the first 1-2 months and later will try to relocate to Zurich or Zug.

Thanks in advance!

No, not at Federal level. You'd need to check if there are any requirements in the cantons you plan to live in. Zurich for example iirc requires training if you have a dog over a certain height/weight. Also it may depend on what breed of dog you have. Some breeds and mixes of those breeds are banned here.