If you haven’t chose your first suit, then please let me help you with that. I think the most traditional and classic suit is three button suits. These suits are very practical as many men have worn them for many years ago.
Nowadays, three button suits come in different fashioned divisions. Tree button suits look better on tall men (on short men they look baggy and make them shorter).
It’s an unwritten rule, that two top buttons should be fastened and last one not. Usually three button suits give you a formal appearance, as some of them come in 3 pieces with vests.