I usually have the party band together as part of their backstory, so that we don’t have to roleplay for the upteenth time the characters getting to know each other.
But if we start as strangers, I don’t see anything wrong with the usual tavern or festival. The first session is a bit critical from a roleplay perspective because everyone is playing new characters and is focused on getting the “feel” right, so I don’t mind easing the job for them by placing them in a well known and established setting such as a tavern: in this way, they can relax and think less about their surroundings, and more about their characters.