Hope you are fine..
- The expression "yalla niro7" specifically means that we will go to somewhere, or suggest going to somewhere. For example:
1- yalla niro7 elcinema. it means: "Let's go to the cinema"
2- yalla niro7 elmadrasa. it means: "Let's go to school"
3- yalla niro7 elnady. it means: "Let's go to club"
- But the expression "yalla bina" means that we will do something, maybe that we will go to somewhere or to do anything else in our place. For example:
1- yalla bina nezaker delwaqty. it means: "Let's study now"
2- yalla bina nebtedy elkors. it means: "let's start the course"
3- te7eb niro7 elcinema? - Ok, yalla bina. it means: "Do you like to go to the cinema?" - "OK, let's go"