What I would do is head down into blighttown and slowly make your way down to the bottom. At the bottom there is a bonfire and a strange looking elevator that leads back up that is very useful when coming and going from blighttown. Beat the area boss and you'll have access to another boss that is very easy and gives you a bunch of souls. There really isn't any need to farm for souls in this game. If you kill all the enemies and bosses, you'll have more then enough to be doing killer damage.
As for weapons I would also reccomend the claymore. And when it comes to stat allocation, a trick is to check how much damage is increased with each point in the leveling menu. Whichever increases your damage at a faster rate, pick that but continue checking because at some point it will switch. You don't even need to understand how the alphanumeric value of the scaling works because you can just monitor the damage in real time to make sure you're always getting thr most out of your points.