From my own experience, there are no 100% perfect answer to your question. We are all very different in here, in terms of skill and experience, and we have WILDLY varying ideas of what to build and WHY we are building.
The reason for me ending up here, is that I had a crazy idea that eventually led me here. (I wanted to build an electric water turbine, without nearly ANY prior knowledge…)
If I’m going to give an advice based on my own experience and learning - it’s to make set small goals at take it from there. If you get the MPCN to mill steel for a mechanical machine, then you are going to have rough time - it’s a loong way to get there.
If you consider this a hobby project, you’ll have a lot of fun, if you are planning to use this for a business idea, without much prior skill - you’ll soon have deadlines and troubleshooting breathing down your neck. This community is of great help, but that doesn’t help anyone with a business project that is not sustainable in the beginning.