D&D and Isolation
Your players should feel isolated.
When playing games in an "old school" or "classic" style, campaigns often look like this: The players arrive in town, they start poking around, discovering the locale, while you give them hints, knowledge, rumors and whatnot before they pick a channel and go. This is quite possibly the only good way of introducing a campaign that puts player action and agency first, aside from doing the same, but placing them outside an introductory dungeon.
Chances are, you're already doing this, at least to some degree. It's basic storytelling, let alone game design. "The party of outsider heroes arrives at town" is pretty ubiquitous in fiction. The key word here is "outsider." The players should be outsiders, and feel as such.
If we want to ensure our players have the most agency possible - the end goal of a game, after all - then we have to make some concessions. One of those concessions, I believe, is the necessity for the players to have no ties to the region. They should effectively be aliens, in the purest form of the word. It should be frowned upon to have the players be "from the area" or have preexisting relations with NPCs, as that removes the aspect of foreignness.
The central conceit of any classic D&D adventure should be the word "necessity." In the milieu, the players are nobodies who are adventuring for the sake of necessity. For one reason or another they are unable or unwilling to achieve gainful employment other than the adventuring life, and this should underpin everything. The primary motivation for both the players and the PCs should be obtaining gold by fair means or foul. This is why D&D 5e's background system is so ridiculous. It's realistic and verisimilitudinous to have a fighter previously be an urchin, or a criminal. It's much less so for him to be a merchant or noble, or even a soldier. Why are you here if your family is wealthy and well-connected?
That aside, the necessity of the adventuring should feel like necessity. Of course, as players, it's fun to throw a bunch of stat lines at other stat lines to gain gold and XP and gear. For the PCs, it should feel necessary. In order to foster that tone, the players should never be complexly welcome in the hub town.
The only things that the players should take for granted is that the town is relatively safe, houses a semblance of society, and provides a resting place. The world should feel indifferent to the players' existence. Because of that, the characters should feel indifferent to the players. There are no "friends" here, only brothers-in-arms. The isolation should underpin the proceedings, because otherwise, it's easy for the players to start poking at the world the gameplay creates: "The barkeep and I are great friends! I think he would love it if I worked in the kitchen. Now, I have no reason to continue adventuring!"
It's not like this is an instant fail state. In these situations, I usually just fall back to the Goblin Punch retirement system. They'll either admit to being kidding, or get a new character from level one. The issue is that it creates idiosyncrasies within that "necessity" conceit. I think a lot of the player expectation issues from modern D&D are related to this.
Personally, I'm here for beer and pretzels and stabbing goblins in the face with a long sword. Not beer, pretzels, and poetry night at the tavern the players collectively own and operate. If they want to do this, that's fine. Again, either adapt, or make a point that "this is the way that I am willing to run the game, take it or leave it." Regardless, the way you convey that sense of necessity is to ensure that your players are never completely at ease.