Help on Improving Gear (New Player)

Hey guys,

This is the first league I have participated in POE, game is fun but ive hit a bit of a wall with mapping. I am currently running T11 maps at the highest and maps are a death sentence as I will most probably die once or twice in a map making levelling up hard. I want to know in which way I am able to improve the gear I am currently using and what are the best methods as a new player to keep going through maps. My end goal is to be able to fight an Uber boss.
I am currently running a toxic rain build I found on the forums and trying to get through syndicate missions to get flask prefixes I need. Any help is appreciated. Cheers

Try to get more life on gear!

Run blue maps or white maps even. Max resists and get as much life as you can then obviously evasion or spell suppression.