if you want a hiro good at combat, which is a good starting point, warrior is the best start hands down. Once you know the system, you can perform with a character built less specifically for combat, but having raw stats to fall back on makes the learning much easier.
strength increases your damage with most weapons, and makes enemies lose more balance/stamina as you hit them
endurance is probably tied for most important stat for a fighter that can't oneshot everything. It affects your stamina, what armor you can use, and directly subtracts from how much damage you take.
agility it the other stat most important for a fighter. It increases damage with most weapons, keeps you balanced (losing balance is basically an insta lose because it forces you to go prone), it lets you dodge attacks, it lets you land attacks more often. It's the god stat for moment to moment combat.
perception lets you see what nodes are coming up in the overworld, but more importantly if it's high enough it lets you read what your opponent is going to do on their next turn. Unless you're horrendously overpowered this is very good.
magic does little unless you choose to be a dedicated caster, which is a whole other system that largely ignores stances and normal combat rules.
charisma is good for seduction builds and recruiting companions, but we'll just ignore those because a good fighter doesn't need to do either.
character generation: warrior with max agility and the other points into strength, perception, and/or endurance. If you have achievement points to spend, extra stats is excellent because these have a huge influence on everything in combat. For perks, faster for the extra agility is just the best one to start with. the second perk can go into increasing strength, perception, or endurance, or you can toss it to skilled to get more stances to experiment with.
skills: you always start a fight at balanced stance. The second + rank of any skill does the same as the first rank, but a little more efficiently. Getting the first rank is most important so you have your combat options, upgrading them later is just bonus that makes you a lil stronger.
from balance: low blow is a poke that isn't really meant to do damage, but does a little and can trip people if they're already faltering. your main attack is going to be spring attack to go into an offensive stance. Block is also good if your opponent is about to do a big hit, or you're low on stamina/balance.
in offensive: you're more vulnerable but are able to do damage. tempo attack is just a basic attack that keeps your stance, but staying in the same stance too long makes you predictable and your opponent will probably just start dodging all your moves after 3 turns or so. combat guard backs you off into balanced while protecting you from an attack, while crushing blow returns you to balance AND does big damage (HUGE damage against a prone enemy) but costs a good amount of stamina. blitz attack puts you in blitz stance which is extremely aggressive. you'll do big damage but also be very vulnerable and burn through stamina hard.
in blitz: all-out blitz is basically tempo attack again, but in blitz so it hits harder and spends more stamina/balance. hold back does nothing but shifts you back into offense stance. Blitz by default is kind of a dead end where if you don't win the fight right away you're over-committed to attacking. I recommend you start the game buying 2 skills here to make it not a dead end
- changeup is like hold back, but instead of doing nothing, you attack while stepping back into offense stance. This lets you swap stances to avoid being predictable without wasting turns.
- Vault automatically dodges any low blows, since you're jumping, and also sets you up for falling crush on your next turn. a SUPER hard hitting move that puts you all the way back in balance stance. A great way to finish your attack and be ready to fall back to defensive if your opponent lives. Just be warned that the dark knight in particular is immune to vault. She will catch you before you land and you'll be caught between a cock and a hard place.
that's the offense down. back to defensive stance which we skipped over before. advance sucks. don't use it unless you're a caster. guard does exactly what you'd think it does. careful attack puts you back into the offense once your opponent is done wailing on your shield and you've got your stamina back. sudden advance is the same but hits harder and costs more stamina.
- second wind is a good skill to buy at the start. It lets you recover stamina very fast in defense stance, at the cost of defending yourself slightly less well than blocking. Good for after you've blocked a couple times and your opponent is running out of steam.
- if you have extra skill points, sudden attack is careful attack but stronger, at the cost of more balance and being less able to dodge
The last skill I recommend you start with is uppercut from the kneeling stance. Ideally you won't need it, but if someone trips you, you're in a really bad spot, and having a move that gets you back on your feet while also doing damage is a huge improvement over slowly standing up and wasting turns getting hit and doing nothing about it.
As a warrior, you'll start with a broadsword. You'll want to replace that with a gladius as soon as possible. it'll halve the bonus you get from your strength and agility, but add 4 damage. Unless you have more than 8 in both stats, this is a direct upgrade. and If you do have more than 8 in both stats, then you're powerful enough that it doesn't really make a difference and the gladius weighs much less
gladius is imo the best weapon in the game. rapier is best if you only have agility, but gladius is best if strength and agil are within 2 or 3 stats of eachother which is almost always.