first of all, build planning is very veryyyyy important, u wouldnt want to reach lv70 to realise your build isnt going to work. i recommend the poemate phone app (not mine, just personally i find it really useful for planning)

secondly, determine what u want to use as your main damage dealer, melee skill? minions? totems? i recommend melee for newbies as its very easy to learn the game mechanics first before moving on to minions etc. u should google for poe berserker/juggernaut builds using Sunder. easiest build to start the game.

third use, poe gamepedia for everything, use poe.trade to get some uniques that will make your game progression easier. then pretty much everything else is self learning through deaths.

lastly, if u're a masochist please do go ahead for hardcore abyss league, otherwise just go for abyss league to enjoy new and fresh contents