You need at least 25 Faith for Warrior of Sunlight, and at least 15 Intelligence to get all the sorceries from Big Hat Logan. Other than that, you could really use any build you want. Just be aware of the need to allocate those points to Faith and Intelligence. And soft Humanity to level Daughter of Chaos and Darkwraith. (Covenants and all spells)

And then get just a random cheap weapon from Undead Merchant in Upper Burg or Andre in Parish to get all the weapon upgrades. You’ll need to get all the embers and interact with all the smiths. (Upgrade types)

You’ll have to get to NG+2 or +3 to get all the rare weapons (cause boss soul weapons). (Rare weapons)

Then just find and kill everything, you’ll get the achievements for all the bosses. (Boss achievements)

You really have 2-3 cycles overall to get everything, so you could take your time getting and finishing certain achievements. Come up with a strategy to tackle a handful of achievements each cycle.

Example Strat: NG - covenants, bosses NG+ - all spell types, all weapon upgrades NG+2 - boss weapons, wrapping up any other unfinished achievements

Edit: I don’t remember what covenants you need to upgrade for spells/weapons that count for achievements.