For the default setting of 1625, there are a couple of prevalent campaign styles I see a lot of:
Exploration and dungeon crawls. Big Rubble, Upland Marsh, Snakepipe Hollow, Prax, and the Shadowlands. Explore the setting, fight non-humans and monsters, and take the treasures.
Community-centered games. Start with a city or village and get your players immersed in the issues of clan, tribe, and kingdom. Your rivals are other clans or tribes as much as they are monsters and non-humans. Many exploration and dungeon crawl games develop into these.
The Troubleshooters. A variant of the community-centered game, here your players work for the local ruler or a temple, dealing with problems. Part knight of the round table and part A-Team, this sort of campaign gives you a community-centered reason to go exploring and dungeon crawls. Arguably the easiest for the GM to manage on the long run.
The Hero Path. Here the players go on magical exploration and seek the support of their communities and cults to eventually become heroes. Kind of a combination of all three previous types, many campaigns end up on the Hero Path once the players start becoming rune lords, priests, and shamans.
Now obviously, the campaign style tends to change with time and development of the setting. A campaign might start as a mix of exploration and community in the Big Rubble of 1625, become trouble-shooters for Prince Argrath in 1627, and start down the Hero Path in 1628 or so.
Troubleshooter is also a popular style. It does mean you need a regular “quest-giver”, be it a ruler or temple, and some narrative arc for the quest-giver (lest it end up being toss a coin to the Witcher style repetitiveness). But it gives a good reason why the players get involved in trouble and do the things they do (the “call to adventure”).