Game access at level 80
You’re right that you can go anywhere at 80. You’re only restricted to Silverwastes while trialling the boost, once it’s permanent you can leave the map. Everything below level 80 (personal story, low level map completion etc.) will still be accessible and I can’t think of anything else that would restrict where you go.
I strongly recommend you do the first part of the Heart of Thorns storyline first, because then you unlock access to masteries and can start levelling them up. Although if you don’t all that will happen is any XP you earn while they’re locked is wasted and you’ll have to start from scratch when you do decide to do it.
Season 1 & 2
You’re right that Season 1 is not accessible. You have two options for playing Season 2:
1) If you just want to play through the storyline you can find someone who has it unlocked and is willing to go through it with you, group with them and play it that way. You can do the whole storyline but won’t get any rewards or achievements.
2) You can buy chapters in the gem store for 200 gems each or 1280 gems for the full pack (20% saving). This means you will have permanent access to it on all your character, including new ones you create in future, you can do the instances as many times as you like, get the achievements and get rewards for playing them.
LFG Tool
I’ve only played games with GW2 style group finders but as I understand it the second one is correct. All it does it let you advertise for or find a group. There are different categories for different areas of the game so you can easily find groups doing the activity you want and groups can add a message to specify what they’re doing (e.g. speed clear vs. normal run) or who they’re looking for, but you have to manually choose a group to join and all it does is add you to the group. You then need to make your way to the map/dungeon they’re in to actually play with them and going through it is exactly the same as if you’d formed a group any other way.
Adventures
They’re basically mini games. I’ve only done a few but some are essentially jumping puzzles and others are ‘collect/kill/tag as many things as you can within a time limit’ or trying to get through an area using special skills.
Elite Specs
You need to collect Hero Points (aka Skill Points) from Hero Challenges around the world. These have a yellow arrow symbol. The best ones to use are the ones in the HoT maps because they give 10 points each whereas ones in normal maps give just 1 point each.
(I’ll leave build suggestions to people more knowledgeable about necros.)
Crafting
Tailor is a good one to choose if you’re playing necro because then you can make your own armour. I’d suggest a weapon crafter as well (Artificer or Weapon Smith, there’s Huntsman too but I don’t think Necros can use those weapons) but maybe wait until you know which weapons you want to use before you do that.
Crafting can be confusing at first but there are some really good guides out there, and once you get used to it it’s not too bad.
Cool thanks.
So how do I start the HoT Storyline, as far as unlocking the Mastery portion? Do I just again need to leave the Silverwastes and lock in the boost first?
I will probably end up buying the Season 2 pack as I like to have access to stuff in case I wanna do it