Cleric/Fighters have access to both the peerless martial focus of fighters and the versatile spellcasting of a cleric. The classes don’t have a lot of direct synergy, but they also don’t get in each other’s way at all, and virtually any mix of fighter and cleric levels will probably make for a satisfactory experience.
Leaning further into fighter creates a character who is mostly just a warrior, but has a smattering of divine magic. However, even just one level of cleric will give access to *shield of faith* and *healing word*, which will stay useful even into the upper levels of play. In addition, a cleric/fighter can pick up a damaging cantrip like *sacred flame* which scales with character level, giving an otherwise melee-focused character a useful ranged option that doesn’t require switching weapons. At higher cleric levels, *spirit guardians* will make a fighter even more dangerous than they would otherwise be, damaging and slowing enemies before they even lift their weapon.
Focusing more on cleric levels creates a powerful divine spellcaster that can stand in the thick of combat with even less feat than a normal cleric, and a roughly even mix of levels gives you a very flexible mix of spellcaster and warrior who can handle a wide variety of different situations.
[[Synergy Feats for Multiclassers#Cleric w/ Fighter|Cleric - Fighter chains and ideas]]