for a 1st run, in which you dont know what weapons there are, and what weapon you like just try to level up STR or DEX according to the weapon you just found that you want to use.
u find a weapon? equip it even if you dont have enough power to use it correctly, go to a safe place, check the moveset: 1handed quick hit, 1handed slow hit, Forward + slow hit, press B + quick hit, run + quick hit, then repeat using 2 handed.
If you feel you like the weapon, check its requisites, match them and use it until you find a weapon you like more and repeat.
You wont need too much str and dext to equip like 80% of the weapons.
Im lvl 90 and i only have like 30str and 20dext, i can use almost any weapon, except some very specific ones that need a TON of str or dext or something like faith. When I have too many souls and im afraid of losing them i level up HP, END, and a bit of Vit (+ equip weight), you can never have enough of that.
Whenever you start a 2nd playthrough, you can, this time, start from the beginning knowing which weapon you are gonna use this time and get the minimun secondary stats for that weapon
or... there is an item now that resets your stats and give you back your souls, right?