if you have the patience and/or luck open up the Land Of Carnage, since as you put it youre a "noob" heres how:
Step one: find the ticket scalper in the item world, one can appear in mystery gates that sells the chapter 1-5 X-Dimension maps on floors 1-49, the other half (chapters 6-10) on floors 51-99 clear 40% of these levels
Step two: you need the P-Flonzor X parts, and SPECIFICALLY the P parts not G or U, heres where to get the Monsters you need to capture to interrogate to get chests that MAY contain the parts you need:
Rear - Rifle Demon from normal dimension 9-6
Left side - Thanatos from X-Dimension 7-3
Right side - Prinny from X-Dimension 7-6
Top - Magic Knight from X Dimension Final episode-1
Head - Professor from X Dimension Final Episode-1
to make it slightly easier on yourself save before asking the captured monster to reveal a chest location, this way you can reload and try again if you dont get the required part.
however there is one more part you need before you can go to the LoC and its the hardest part to get:
the last ship part is held by the meowkins pirates who ONLY spawn in the item world on floors 91-99, I had actually quit playing D4 because i had spent hours upon hours tryin to get them to spawn months ago tried for a half hour yesterday got them to show up, and now serveral chars are now 9999 and i also have a trapezohedron, but i digress....
ANYWAYS you need to wait a few turns between said floors and just wait for them to show, then if and when they show, just kill them all you get a notification that you've obtained the part.
IIRC you need to assemble all the ship parts into a full ship in the pirate editor and then if you have the 40% X maps cleared yo you can travel to the LoC.
from there you can grind MoO 4 for a while and you can get units to max lvl fairly easily, i had about 100 staticians on an item and it took me 25 mins to go from about 3500-4k to 9999 give or take depending on your units lvl and class, and if you dont have staticians it'll just take slightly longer to hit the cap
Kill for gain, or shoot to maim, we don't need a reason.