Can you try out subsistent farming?

I come from a farmer's family, we make money by selling out surplus produce. We sell rice, corn, lentils, and mustard. While I believe everyone should try subsistence farming, there is no harm in earning by selling surplus.

As we live in a city which is too much populated and the land cost is too high so we don't grow vegetables here but still some of the things we grow in the pots on the terrace.

Well, in my own understanding, subsistent farming takes a lot of work but to be honest, it is quite rewarding if you are able to do it. Growing what you eat helps you to appreciate the value of food the more. I also have a small garden in my backyard but I want to make it a little bigger so the food I get from it can be sufficient for my household. I just want to grow some stable crops like maize and cassava.