Agreed you should largely ignore this event, at least for the first few days. Leveling Bashira, Leanne and Mia/Iris (or Alissa if you're short on gold) is your priority. After them a duelist, Katie, Belinda and Yuyu (hopefully you get a better mage than Valerie, if not you'll have to level him too; Pallis the female silver mage is better if you get her). Daniela is generally better than Soma but Soma starts with a huge head start in affection and yours also has a massive level advantage so at this stage, where you're leveling a lot at once, just stick with Soma for now as your second archer. they're both totally outclassed by Spica (who outclasses all archers except Nanaly the Black and Bashira for burst damage) who should be a priority acquisition once you can manage at least Crystal Keeper N, if not H (Mia will help a ton here if she's leveled)
I see Phyllis is 49, she's actually functional for what she's supposed to do (generate UP) at Level 50 Pre-CC, so you can leave her where she is for the most part. ToTeras mentioned Cloris, but honestly you have Yuyu and Belinda, both generally superior witches so while you can and should do her challenge maps to pick up the free silvers and her, I wouldn't bother leveling her.
For duelists, Lolonee and Cypria are your only viable options, Elaine is meh at best 99% of the time. Depending on how many CR you got on Lolonee, you might prioritize Cypria despite her dependence on RNG simply due to UP costs.
If you find yourself running short on gold, sell iron fodder from story maps rather than using them in combination.
TLDR: Acquire Spica ASAP
Level Priority:
Bashira > Leanne > Iris/Mia (Alissa if gold is an issue) > Katie > Duelist > Soma > Belinda > Yuyu > Valerie
Once you get 200 DC, grab Spica and start leveling her ASAP (replace Bashira with Spica since by the time you get Spica Bashira should be 50CC30 at least)
NEVER CC/CE A UNIT YOU PLAN TO USE BEFORE LEVEL 50!!! I CANNOT STRESS THAT ENOUGH, FAILING TO DO SO WILL PERMANENTLY GIMP THE UNIT'S STATS!!!