Eh, you get it. In the first game you can avoid the first boss for a bit, and it's not that hard to fight him as long as you manage to land your drop attack. You are already hallowed when you start, so it doesn't really matter how many times you die, you aren't losing much.
The third one is a bit trickier to start, but still totally doable. It really doesn't matter if you die, because all you lose is souls, and until you beat the boss your souls are pretty pithy. Use the tutorial enemies to get a feel for the controls. Fight the boss. You'll get him eventually. If you are a pyromancer save your fire ball until you've weakened him some, they are more valuable in the second half. Your axe is valid. This boss is completely dodgable if you time it right also. It's not how I chose to start off, but I've seen people wear heavy armor and let him hit them at a certain point in his attack in order to get a good hit on him. In any case its completely doable.
The third one is a bit trickier to start, but still totally doable. It really doesn't matter if you die, because all you lose is souls, and until you beat the boss your souls are pretty pithy. Use the tutorial enemies to get a feel for the controls. Fight the boss. You'll get him eventually. If you are a pyromancer save your fire ball until you've weakened him some, they are more valuable in the second half. Your axe is valid. This boss is completely dodgable if you time it right also. It's not how I chose to start off, but I've seen people wear heavy armor and let him hit them at a certain point in his attack in order to get a good hit on him. In any case its completely doable.