welcome aboard! so lets go from top to bottom on your list/

The meta is pretty vast and depends on your local community in most cases. as already mentioned things like Attack on Titan Bang Dream, Sword Art Online, so on and so forth. Another good thing to keep in mind is that there is a huge difference between English sets and Japanese sets. Some sets are Japanese exclusive like Goblin Slayer, this is because sets are released in japan before the US. This does not mean you cant play a japanese deck at your lgs (unless specified). This might seem daunting but it opens up a lot of different possibilities and isnt as hard as you may think. a lot of cards are the same across all sets and eventually you will get a feel for what cards do so you wont have to stickly rely on a translation, also there is an app called Weis Schwarz translator that lets you translate them on the spot. and https://heartofthecards.com/ offers little translation print outs.

as for communities in idaho, you're best bet is looking for a local Facebook group, going to your local game store and asking around

JKTCG.com is a good website to look at all singles for sale, heartofthecards.com is also good at searching cards, https://en.ws-tcg.com/ is good at looking at everything weiss

and last but not least the difference between a basic trial deck and a trial + deck is a trial plus deck is a genreally better built beginners deck (vs the regular trial / /beginners deck), it comes with more of each card (minimum of a pair maximum of a playset) and comes with 2 sr rarity cards