New player, help needed

I've not been playing too terribly long. I've completed the storyline and made level 76 as a Ranger. I'm now having some serious issues with defense against some of the monsters I'm encountering. Often I am being one-shotted and killed. I'm seeking suggestions on gear, maybe, to help with damage mitigation and survivability. Please help, suggestions are welcome.

You need to go to account settings and untick characters are private or no one can help you.

General advice without looking at the character would be have at least 3,5-4k life (by combining life increases from passive tree and life stat on items) when starting maps aiming for more later, have all the elemental resists capped at 75%, and have appropriate flasks to remove deadly ailments like bleed or freeze.