What are some advantages to being unicellular? Multicellular?

As a unicellular, you’ll be able to reproduce very quickly and you won’t need a complicated organ system. Being smaller in size can be an advantage of being a unicellular organism.
And as a multicellular, you’ll have competitive advantages of increasing in size without having limitations. They can have longer lifespans when individual cells die.

Ineed more info for this, i don’t quite understand what you’re asking.