The best approach to commuting and cycling as part of your daily lifestyle is to not overthink this and just get on the bike. At least have some gear in case it rains, gets too cold and a bike pannier to throw in stuff that you might buy along the way.

And not overthink how much you're going to cycle before you spin the wheels. But just do it and enjoy it. Then you get better and better without analyzing it much. Pretty soon, you realize: wow, I biked this much today..but I had fun/enjoyed myself.