Thronebreaker isn’t really much like either the main Witcher games nor Gwent as far as gameplay goes. More like Shandalar really.
You wander around on 2D maps gathering resources, making roleplaying choices, solving card-based puzzles, and engaging in simplified/modified games of Gwent. Most of the choices are minor and only affect your resource totals or morale level, but quite a few determine what bonus cards you’ll have access to and some affect battles that may appear down the line (sometimes even several maps later). The puzzles are intuitive and/or forgiving for the most part, using custom decks to guarantee each is solvable, but a handful are remarkably obtuse and may require looking up the solutions.
The Gwent battles range in difficulty from laughably easy (any ‘fair’ confrontation) to punishingly hard (the enemy cheats). Most of the hard ones have a specific weakness of some kind to make them easier with the notable exception of the final battles on the 4th and 5th maps; those two are pure endurance slogs. Difficulty is of course also affected by what kind of deck you’ve built, with compositions heavy on direct damage and point removal (e.g. Jade Figurine) generally having a much easier time than others. Which brings me to the last part of the game: Base building.
Most of the resources you collect are going to be put toward upgrading your Camp buildings. While it’s true you’ll end up with far more resources than you can spend by the end of the game if each map is thoroughly explored, you’ll always be needing more in the early/mid-game. Getting the Forager’s Quarters (and upgrading it on the second map) should be the #1 priority, followed by maxing out the Royal Tent (Trinkets are insanely powerful) and Mess Tent (the cost reduction is stronger than a straight cap increase). Once all that’s done you can grab the Watchtower for the Scout feature if you don’t trust manual exploration (scouting is cheap and has a huge range) and then whichever Training/Workshop buildings affect the cards you want to use.
Stay away from the Herald’s Study (recruits should never be in short supply), Cartographer’s Desk (a purely cosmetic effect), and Barracks (with a maxed-out Mess Tent you shouldn’t need more than the first rank of this at most) until everything else you need/want is built. Lumber is what will be in shortest supply, so keep a lookout for choices that give more of it and try to avoid those that require it.
One final thing of note is that unlocking all the achievements requires making some choices you might otherwise prefer not to. Specifically, one Gold Chest can only be found by dealing with a bandit and collecting all of Meve’s weapons requires a mixture of merciful and ruthless choices.
