Good night moms, I'm here again for advice)) We have a low weight, we'…

Good night moms, I'm here again for advice)) We have a low weight, we've been at it for a month, we haven't gained the norm of weight since birth, they said to introduce complementary feeding, who also feeds on complementary feeding, write down how you did? Did you gain weight? How many ml do you give the mixture and how often do you give it besides breastfeeding? We were told to come in 10 days for weighing, I'm worried that we didn't gain weight ourselves.