Chimera is not too difficult either, if you understand his mechanics. He just takes a long time to fight, also has a lot of phases. For the most part he'll just hit POE Orbs you in the face, and most of his attacks don't do too much harm. The only attack he's that's genuinely frightening is that his smoke cloud. He'll disappear and you have to run into every smoke cloud until he hits you and then reappears. Aside from that, he is a breeze.
Phoenix is probably the most simplistic of this bunch, but also very lethal. He's got an attack that whirls forwards you have to dodge, otherwise you turn into a pancake. He also has an insanely strong fire explosion that he charges up for before releasing, so steer clear of that. You'll likely want to clean all of them at some point.
Minotaur is the final of the guardians. He isn't always the toughest, but he does need the most gear. Every other protector has a lot of stuff to dodge or perform around, but maybe not Minotaur. His strongest attack is a burrow. If you get a lot away from him he will go underground and float towards you. It will kill nearly anyone it hits. Because of this, your very best choice will be basically just standing in front of him and taking his strikes. It's more of a equipment check than anything. But you should proceed when he slams the ground and produces a circle of falling rocks; you do not wish to stand at that.
The very first thing which you'll need to decide after launching Path of Exile is which league to combine. Leagues would be the world instance your character belongs to, with a challenge league being a temporary case that is usually introduced with poe skill tree a new update. There is frequently a challenge league accessible, with the present one being Harbinger, as you may also choose to play a Hardcore variant of the challenge league or Standard.