Questions about example sentences with, and the definition and usage of "Primero"

A: First of all give thanks to god for everything and my family

A: First of all.

A: "I am going to talk about the food first," or "First I am going to talk about the food."

A: First and clear

A: First and foremost es la forma más contundente de decirlo

A: × (primero, haré como una presentación y espero poder hacerla bien y me ayuden)

× Hi.

× My name is Fernanda, my surname si Soberanes, but you can call me Mafe, i have ninety (19) years old, i love my country that is Mexico, i like draw people and singing the songs of Camila Cabello, but i don't sing good.
✓ My first name is Fernanda and my last name is Soberanes. You can call me Mafe. I am nineteen (19) years old. I love my country, Mexico. I like to draw people and to sing songs by Camila Cabello, but I don’t sing well.

A: "August 15th" es más natural. "15 August" es más formal.