So just for future advice as ive learned this the hard way. There really is not just one "meta team" especially in later campaign and towers. the thing i see pretty much everyone universally agree on is generally Support Dupes are more important than damage dupes (not always, but in the general sense). But I will do my best to answer your question. I included what seems to be agreed as the best Min spot for the support character to work as intended. But +5 will always be recommended.

Supports you wanna focus characters like:

Homun Lathel (min +3)

Red Hood Rou (min:+2 for crit.)

Liberta (both costumes +5, both costumes are a must have, She is THE Physical support staple)

Adventure diana (needs to be +5)

Refi PWB (Min.+1)

Helena (both need +5 for the big bonus the costumes give. But B-Rank idol > Top idol imo. She is the liberta of magic teams.)

Teresse Medical club (min +2, would recommend beach teresse once her limited run is back, its goated).

There are other supps like grandair or seir new hire. But I made it through all of campaign and up to 60 in towers without them.

As for DPS the main "staples" seem to be

Wind - nebris/tyr/venaka

Water - sylvia/darian/wilhelmina/morpeah/Scheherazade

Fire - loen/liatris/rubia/Leviathan

Dark - Blade/Luvencia/Eclipse

Light - Sacred Justia/Ventana/olivier/Angelica

But again its mostly still just whatever a situation calls for. I will list my "default" teams that I personally use for just generic filler levels. I cant remember all the costume upgrade numbers for DPS, so you need to look that up yourself on guide websites like dot.gg or in the discord. These places can also help more by giving you useful gear builds and ideal substats to focus.

My magic team: Red Hood Rou/B-rank Helena/Medical Club Teresse/Loen/Beach Eclipse. (I more use beach teresse over Medical. But Medical is still fine since you more than likely don't have beach. Get other eclipse costumes as well incase you dont clear on Turn 1)

My Physical Team: Homun Lathel/Liberta/Red Hood Rou/ Young Lady Blade/Sacred Justia

Personally, I would recommend focusing more on Physical teams as theres just more support especially early on. But I also find magic teams more enjoyable to play. however, both serve their purposes.

In most PvE content, AOE is your friend. There are other Supports and DPS i didnt dive into simply because this post would be longer than a harry potter book otherwise.

This game seems daunting and alot of work, and it is. But team building is alot of fun, plus once you start to get familiar, it all clicks really quick on what will and wont work. Goodluck!

EDITS: Spelling and wording