The main thing you are doing wrong is reading howto articles in the web. Most of them are written by newbies who did the thing they describe for the first time, got something likely working and want to describe this for themselwes an for the other world. This does not mean they did everything right, and howtos usually contain numerous mistakes. Better read official documentation. This will take longer time but you will understand what you do. I don’t know if Mint has GUI tools to configure samba server. I would better edit config file manually, it is more or less simple.