One Plan Amplified - Help Me Optimize

Seeing people post about their plans and all their free lines has me feeling some serious FOMO. You all have a wealth of knowledge and have been so helpful to each other, hoping you can give me advice that will help me save a little cash.

One Plan Amplified - 4 voice lines, 2 for $120, 2 more at $20/ea - 1 connected device line (iPad) $20 - 1 wearable line $10

I’ve seen line on us offers in the past but feel like anytime I try to get one they tell me my plan isn’t eligible. Am going to need another line for my daughter eventually, any way I can convert any of my lines to free ones? Does it make sense for me to switch to Go5G to get a free line for my daughter? Do I lose any benefits going from One Plan Amplified to Go5G?

You all are so knowledgeable and helpful, curious to hear what you would do in my position!