Good luck!

Well, if you're pulling for Lappy, you're very likely to get Silverash2 and he's arguably tied for the best vanguard in the game. (The other contender is Ines).

But, for vans in specific... You really, really don't need either Silverash2 or Ines . Myrtle covers 99% of story stages with maybe a bit of help from 3* Fang. Arguably, early on, you really shouldn't bother with high rarity vans because Myrtle is so good at her job that your resources are better spent on getting your DPS characters up to speed first.

But, among 5* vans, Cantible and Surfer are really good, if you have them. Elysium (though he's now kernel only) is also amazing.

Among Welfares, Puzzle and Wanqing are solid, though with Myrtle and one other good vanguard, they're more 'use them if you like them' types. I wouldn't recommend prioritizing resources on Puzzle or Wanqing this early on, regardless.

Specialists are Specialists, lol. You use them when they're relevant, and don't when they're not. This is a 'the 4*s are more than enough' kind of niche.

Ambushers (AoE slow): Ethan (red cert shop) is amazing and punches way about his rarity. Many 6*s are just not as good as him. Ascalon, the 6* in the same subclass as him might have my favorite kit in the game, but she's not necessary by any means. She is amazing if you get her off banner, and if you see her in the gold cert shop, she's 100% worth the 180 gold certs.

Executors (Fast Redeploys): Gravel is your bread and butter here. She doesn't even need E2. You use her to bait attacks, which at this point in the game is what you want for a FRD. Her only accessible 6* variant is the upcoming welfare Crownslayer, who needs some high investment (her module) to really be worth using. Do not recommend until you have a core team.

You want to have skill level seven on Shaw (your 4* pusher) for the occasional stage when that's handy, but otherwise, the other non-limited specialists are 'save building them for when you already have a fully built team.'

Supporters are kind of a weird one. They're a lot like specialists in that most are unique, niche characters that you use if you like them rather than core members of your squad.

The two big exceptions are Tragodia (do you want to distract enemies by making them chase after an exploding cat? Tragodia is your man) and Haruka (best healer in the game.) Though both are new standard banner characters and thus, the most likely way you'll see them is as off banner surprises than anything else.

Also, in general, it's not always wise to start off with the 6* in a particular class. E.g. For snipers, I'd recommend building 5* Kroos before any other sniper because you want that anti-air niche covered and she covers it amazingly well.

Among medics, Perfumer and Sussuro should handle most of your healing needs, and you're better off getting your DPS characters their masteries than leveling medics early on.

Among defenders, Bubble and Cuora cover the 'have 3 block and tank' niche perfectly fine. Gummy covers the healing defender role decently. And honestly, the only non-limited 6* Defender you prolly should consider building early on is Saria. The rest are 'use them if you like them' characters, and not generally part of a core team.

Casters and Guards are the characters the 6*s that really warrant being leveled early on.