What happen if i start my project in Unity Free and then during development i will find out that i have to buy Unity Pro for additional features? Does that mean i can’t port my Unity Free project to Unity Pro? I never developed in Unity so i don’t know if Unity Free will be enough for me or not.
Compare the versions there.
Unity personal includes Engine with all features.
There is probably nothing essential that you will miss in Unity personal.
And there is nothing wrong with starting with personal and later going pro.