Currently Void Mechs are not recommanded for playing:

• Even though personally find Void Mechs most interesting - instead of buying lvls you need to play & lvl them up
  
• If you die with Void Mech you lose total XP from your Mech ->
  
  • You can lvl down
    
  • Its confirmed you can lose more than 1 lvl so its most likely X% out of your total
    
  • Also higher difficulty = higher xp lose
• Due to bug WHICH WILL NOT BE FIXED ANY TIME SOON, if you lvl down and have lower lvl than is needed for equipment (part) that part can vanish - its confirmed you can lose Legendary tier equipment
  
• When asked devs about it on discord (if its possible to lock Void Mechs once you max them), got reply:
  Void mechs are intended to be a "hardcore mode" where there is a penalty for death. It's nowhere near as hardcore as the alternative, which would be destroying the mech permanently.
  
  • Feel free to let me know in comments if you can find anywhere info about Void Mechs being "hardcore more", where you lose part of your xp progress and possibly items on death.

BEWARE gameplay is controlled server side so even if you trust your equip and abilities in case of lag (which happens [server problem], luckily not very often) your mech can teleport to different place (like on top of Enemy Nexus, which on higher difficulty means most likely death.

You need to look for parts with word "Scrappers" in them.
Currently its confirmed there is:
Helm, Torso, Hull, Legs

Personally only found it for green or better equipment (not common, so didnt find mailable part).
Every part increase ~50% salvage gain at equip lvl 50
So if you get all 4 you can get easily +200% Salvage gain.

+Dont forget to use Scrapper Drones (unit) - 4 of them can be around at same time. To collect more salvage (even this collected salvage is multiplied by equip)

Currently there are 2 Ultimate Mechs:
Ultimate Striker and Ultimate Helix.

Both are purchasable for diamonds 1'350 at moment of writing this (normal price, not on sale).
Since you normally don't find them normally in Wastelands, fastest way how to buy them is:

• Write their name in chat (ideally party so you don't spam global chat)
  
• Click on present icon (add to wishlist)
  
• Right Click on it again and you can buy it

(Its kinda stupid method but since Wastelands dont have access to normal shop its fastest)

Wastelands have shared inventory with AirMech Strike.
So if you download it you can daily claim box with random rewards (like skin, key, scrap, kudos)

Currently it consist of 3 basic building:
1. Base: Allows you to equip up to 3 items and allocate skillpoints

• Based on account lvl, you can see your current lvl when you hover over your pilot icon in top left corner
  
• For higher difficulty its best to use items which buffs your AirMech as basic units even with full buffs are still weaker than the ones AI uses
  
• Personally prefer +XP until you get to max lvl (60)

2. Hangar

• Lets you create Different Loadouts for mechs
  
• Up to 8 ... there are 9 mechs
  
• Hangar slots all use same items & skillpoints selected in Base (So you cant have Melee oriented Bomber build, unless you want all slots to have melee buffs - even if they dont have any melee attack)
  
• Usable in case your AirMech is destroyed in match (on maps where there is "Nexus" base) you can select different hangar slot.
  
• Parts are not shared so they can be equiped on only 1 slot at a time

3. Depot

• Let you restock charges for units you summon in matches
  
• Let you upgrade it (up to 2× number of charges)

Those are the basics you should know (and which should be obtainable ingame, and not here).
If you think there is something I should add just let me know in comments.

PS: Even though "devs" are currently trying to destroy their community, this is actually pretty nice game so take care and have fun with it.