You get plus 2 to constitution, and a floating plus one.

Your a zombie so life threatening damage isn't so much of a problem for you compared to the living. As a result you get advantage on death saving throws, and the ability to make a constitution saving throw to drop to 1HP instead of hitting the floor.

You no longer require food, water, or sleep and are immune to exhaustion, poison, disease, and necrotic damage. You are weak to radiant damage, but have a resistance to necrotic and poison damage. You also have disadvantage on persuasion, and deception checks with people who know your identity and are not friendly.

You get 60ft of dark vision not much else to say.

Your a walking corpse that isn't decaying anymore so your life span if effectively indefinite.

Your a sentient zombie, so you alignment is up to you, and your GM though being that your a monster people aren't going to like you that much.

You can speak, read, and write Common and one extra language within reason.