Everybody thinks playing a fighter is easy…
Generate lots of damage dice, and get your attack as high as you can…
Stand out in front and tank all the damage.
This works, until you reach the mid-high levels and then your fighter goes down fast. Playing a fighter is NOT one dimensional. This is what I consider KEY when playing a fighter. You can focus on the type of fighter you want to play, and what feats to use- but more than any class the fighter’s gear and damage reduction is live or die.
Each time you level up, you need to make sure your gear is keeping pace- a +1 sword at level 2 is great, at level 9 it’s a problem. You need to find, craft, or upgrade your weapons as you level up. At the same time, at the lower levels armor class is important- magic armor, shields, and rings all keep the damage off. But at the mid levels that starts to change- many of the monsters encountered will have insane bonuses to hit you- so spending all that coin on armor class is not efficient.
That’s not to say armor isn’t important, but damage reduction and resistances become more important. Along the way you will also want to boost your strength into the 20’s and have an alternate way of mobility.
As the Dungeon Master, at some point it will be hard for my minions to beat down the fighter, so I’ll look to swarm her, or keep my big boss away. Boots of flying, boots of speed, elevation, etc. make that harder for me as the DM. And finally BYOH (bring your own heal)- the cleric can’t be everywhere at once.