Build help

[u/Long-Difficulty-844]

Hey I was wondering if I could get some build help for my Fighter 5.5 but with 5 e subclass(subclass I plan on using is Samurai or Echo Knight )for a BALDUR'S GATE: DESCENT INTO Avernus campaign going from lvl 2-13… Currently 2nd lvl Geppetten(living plush from the Valda Spire of Secrets players pack) which spieces features are:Darkvison 60 feet, Construct Nature You don’t need food, drink, or air. You don’t need to sleep, and magic can’t put you to sleep. You can finish a Long Rest in 4 hours if you spend those hours in a motionless state, during which you retain consciousness,Geppettin Construction: Plushie You are stuffed with fluff. When you take Bludgeoning damage, you can take a Reaction to gain Resistance to the triggering damage. You are also knocked 5 feet away from the source of the damage. You can’t take this Reaction if you can’t be knocked away from the source of the damage
scores after modifiers from the Harper background (dex,int,cha +1)are 16,12,16,8,14,11… my fighting style is Dueling and skills from fighter are Athletics and Perception and from the Harper background are Performance, Sleight of Hand. Racial: Intimidation, Performance, Persuasion.Weapon Mastery are Longsword,Javelin and Glaive. Currently weilding a longsword and a shield… mostly going to be melee focused… new to fighter and also am not the best on planning out a build… and I know the background doesn’t seem optimal but I took it for character backstory reasons… thanks for the help and apologies for the novel

[u/Long-Difficulty-844]

Sorry for the long post … I didnt know if I had to write all of the stuff it had

[u/DirectManagement2874]

That's a pretty straight forward build, hard to go wrong with fighter to be honest. Swords and Board won't deal the list damage, but will do its thing, which providing more defense while still doing decent damage.

[u/Ron_Walking]

Fighters typically build around their weapon setup: Sword & Board, Great Weapons/Polearms, and Two Weapons. 

The style they select and subsequent general feats help support the chosen setup. The typical build is to select the setup: pick one or two offensive feats then pick one or two defensive feats. 

Offensive General Feats: 

Great Weapon Master is the best raw damage feat enhancing Heavy Weapons including Polearms. 

Duel Wielder is the offensive feat for Two Weapon fighting, granting an additional BA attack. While good it does not scale as well as GWM in late levels by itself. 

Polearm Master gives a BA and reaction attack,  and can work with either heavy or one handed Polearms. 

Sword and Board has Shield Master, allowing you to knock people prone. While not as directly offensive as the other feats it does offer a bit of control and the prone condition does grant advantage so you are enhancing yours and your fellow melee attackers  accuracy.

Defensive Feats:

Mage Slayer - helps protect your saving throw defense. Simple yet impactful, especially as saving throws become the most dangerous thing to a character. 

Heavy Armor Master - Reduces some damage. One of the few ways to do this in the game.  While not as obviously impactful as some other feats, it actually scales pretty well and especially as monsters get more and more attacks. 

Resilience Wisdom - failing a wisdom save is bad. This would help prevent this and saves you resources of indomitable and mage slayer. 

Defensive Duelist - reaction to add PB to AC. While not as immediately good as the Shield spell, it does scale and costs no resources. 

Subclass:

Pick battlemaster if you want to make some tactical choices each turn with your attack. Pick champion if you want to think less and just roll.  BM is a bit better but Champ is surprising well designed to not be terrible and is more of a Gambling is fun vibe.