Starting cereal - advice wanted!

Anyone have to/wanting to start giving your babe cereal? My ped told me to start my girl on it today because her weight is a little low :( Shes exclusively breastfed so I was planning to wait until closer to 6 mo to start on foods but we gotta do what we gotta do. How are you scheduling it in with your LO’s other feedings? We have to give it to her 3 times a day which seems like a lot so I was thinking of starting out maybe twice a day then working my way up? Idk. I have no idea how to do this! Lol. Please let me know any info you have about starting on cereal! Thanks so much. Cute pic from her first time trying it this morning!