Yet another Newb with questions

Hey there!

Just recently finished the story, and did a full rework of my passives with 3.13. Which seems to work fine, but here's the thing: my gear is not up to snuff. That's fine, i need upgrading and i am aware of that. So here are the questions:

How do i get the necessary gear from the guide i am following? (https://www.pathofexile.com/forum/view-thread/2642810)
It lists a few rares and uniques, but trying to buy them is just ridiculously expensive.
Trying to get their base drops and upgrade them myself seems to be very hard, even the regular filter seems to exclude base items. And f.e. going for a delve and check out the armor drops on a node is just ridiculous. Way too many drops which i cannot stand to look through with those clunky controls.
Any tips on how to get the necessary gear?

Another question: do i have to use the gear mentioned in the guide? e.g. for head the only option seems to be "the baron close helmet", is this really the only one i can use? or can i go for a higher/lower base item?
if i get the base item, can i make it unique? Or does the unique have to drop?

Also on trade market i can find unique armors like for example "geofri's sanctuary elegant ringmail", but i also find f.e. "loreweave elegant ringmail". Does it matter which one i get? And what if i just use any rare "XY elegant ringmail"?

What should i prioritise given the choice: correct gear with wrong slots or go with the wrong gear but the correct slots?

So yeah, maybe you can see now why i'm currently just stumped and i have no idea how to continue on into endgame at all.

I have quickly checked the guide, i think you should be fine without the rare listed, part of the gear he show is for maximazing the build.

Fisrt of all, you have to always check the price of items needed for a build before making it, some build can be very hard to make depending on your game experience.
Good rare are the most expensive gear to get and to find (because of how the trade work on console).

Secondly, when you follow a build, you follow it completely, if you change something and you don't have the knowledge to be 100% sure that the change will be better, you stick to the build as showned.

For your loo filter, you should make your own or at least look for differents ones that players make, you should find a good one. and Don't try to build a rare for now, you will spend too much currency without getting the mods you need... Crafting good rare is for experienced players haha.

For the Helmet, if the build rely on heavy strenght, yes, the baron is the best thing you can get, but if you play a different minion than zombies and strenght isn't in your build, you can go for any helmet with +2 lvl minions.
Depends on the unique, some unique can be chance, some don't. you have the info on the wiki.

Take goefri's, the lorewave will make any good for your build. If he he listed this armor and not the lorewave it's because i tried everything in pob and came with the best options for the build. So again, stick to build :) It's not "elegant ringmail" that is important, it's the mod on the armor.

Correct gear with the wrong slots, you can always change your slot way easier than your gear mods.
The most important thing is to get your max elemental resistance (so prioritize this on your rare gear, even if you don't have the right sockets)

That's kind of a really overhyped guide, especially since the nerfs to multiple minions and the Necro ascendancy overall. I would much rather advise you, as a new player, to go for guides specifically targeted at new players and acknowledged by the community as such, e.g. Enki's Arc Witch, Esoro's Lacerate Gladiator, Remi's Toxic Rain Trickster, Kay's Spectre Summoner, and ShakCentral's Vortex Occultist. Beyond being specific guides for these particular builds, they'll also take you through a lot of in depth knowledge of how the game works and how a build like theirs works. This will help you A LOT with understanding where your build can be changed around, and where it can't.

In your current situation, I would advise you to cap out your elemental resistances (75% minimum, as high as 109% if possible), get your life as high as you can take it, and get some attack and spell block. Prioritise a 5 or even 6-link for your main skill, and also getting your other links in place. Then, try to do the hardest content your build can survive and focus on making currency. This can be through doing the Chaos recipe (use the wiki to understand this) or through pure currency drops. Invest that currency into upgrading your gear.