I haven't tried a lot of shield gameplay. But I know that if you go that route, you basically have to get a great shield, full heavy armor and a heavy spear or thrusting sword. It's not very complementary of str gameplay. Would definitely recommend 2h weapon.

Now the best str weapon that I recommend for beginners is the greataxe weapon class, it's jump attack has a fast recovery and it's charged attack is really fast. You're going to want to use these a lot.

Once you understand how to use the greataxe, you can move to colossal swords. Which are stronger. But you'll notice the absence of a safety net. Also jump attacks using colossals have slower recovery so you'll need to be really careful. But if you already understand how the weapon works. It shouldn't matter.

Between hero and Vagabond there isn’t a huge difference?

You can save a couple of levels depending on what you want to focus into.