If you’re venturing into the suit terrain for the first time consider starting with one in a mid blue. It’s not as formal as black and transitions easily from day to night. Dressed up or down it’s the go-to suit for any occasion.
But even the world’s most expensive suits look bad if they don’t fit well. Unless you’re born with the genes of a suit model, the very first thing you should do is have your suit properly fitted by a tailor. For a small outlay you’ll look like a million bucks.