I've seen the comparison, and it fits, that Novice Paths are like Basic D&D classic options, Expert Paths expand to sub-options available in AD&D and later, and Master Paths are like Prestige Classes. You get an ability from your Paths at every level (except 4th level, where you get either a new spell or an Ancestry ability).
Your Novice Path gives you abilities at 1st, 2nd, 5th, and 8th level, and the abilities at 1st and 2nd level are particularly defining for your character. This makes the Novice Path you select the biggest factor in who your character will be. Its more like a specialization than multi-classing.
If you want to dominate in combat, go with Warrior. You get lots of Health and a Boon to all weapon attacks right away. At second level you get an extra 1d6 to all weapon damage rolls. At higher levels you get the option to do extra damage to a single target or make attacks on multiple opponents. Every Path gives the ability to heal yourself one quarter of your Health total once between rests, along with an extra benefit. The Warrior gets to use this as a Triggered Action, so they can do it immediately after taking damage, leaving them free to still fight on their regular Action.
Rogue is good if you want to get away with a lot in and out of combat. You get a Boon to one attack or Challenge roll a round. Since Challenge rolls are used for "skill checks" and "saving throws", it makes you good at everything and hard to pin down. And if your attack Boon isn't negated by a circumstantial Bane, you do extra damage. At second level, they get a bonus turn if they roll 20+ on an attack roll. In the one session I ran where a player had this ability they loved it. It fits the fiction of a tricksy character while also being very "game-y", for players who like to min/max at the table. Rogues also get Talents that allow them to specialize in combat or skill styles, or dabble in magic.
Priest allows you to fight while still supporting your party, and gives you a few spells. When a Priest heals themselves one quarter Health they allow another character to do the same thing, and they can give a Prayer boost to attacks and later damage starting at second level. Prayer can be used on yourself, so its possible to hold your own in combat. Religions include the Cult of the New God and the Old Faith (I love the new church vs paganism dynamic), as well as Witchcraft and Dwarven Ancestors. Spells are more limited than the Magician, you'll likely be picking from just two Traditions for your character, so if you want to cast more go with the other class.
Magician is all about spells. Spells are divided into Traditions and you have to spend a "new spell" to learn a Tradition (Magicians learn both cantrips associated with a Tradition, unlike other classes that only learn one). Your total spells known will seem limited if you're thinking of later D&D options--if you focus on spellcasting paths you'll still only get a total of 13 new spells by 10th level. On the upside, you get to specialize your spellcaster into a Storm Mage or a Fire Mage, instead of having a berth of options but only a few optimal choices.
If the first session where you only have an Ancestry is a prologue, your Novice adventures are about coming together as a party and getting comfortable with your basic abilities. There are suggested options for training for each class, so I'll let some campaign time pass between the first session and the second to allow for the characters to grow and become their class. The first few adventures will be about responding to dangers presented, setting the stage for the characters to become movers and shakers in the world.