For your Helper Squad:
Japanese Iris + Edelweiss (she arrives soon anyway) for the famous Pest Heal Combo
Orchid for Speed and Atk Buff
Camellia for Atk Buff and Def Buff (also has a Bloomed Form later on)
For the last Slot you have different options:
1. Lavender (She is a solid 5* with good stats, has Bloomed Form later on but she lowers your overall Speed quite a bit)
2. Peach (also has solid stats and buffs Atk)
3. Dipladenia (for disabling Web Nodes and an extremely fast Team together with Orchid and Edelweiss, has Bloomed Form too)
For your other 3 Teams i would advise you to make specific Teams.
A few examples:
1. A Team based around Solar Blast Damage / increased Life Crystal Drop etc.
2. A Team which contains Girls buffing each others Atk Stat.
3. A Team based on Defense Stacking (Bipinna, Southern Cross, Water Lily etc.)