How does the initial mass of a star affect its final outcome?
It affects the lifespan and the life stages.
A star needs mass to function so they must be relatively big to produce fusion and to keep from imploding. Smaller stars live longer since they need less fuel to stay stable and they will collapse to white then black dwarves at the end of their life.
Massive stars with more mass require more fusion to remain stable and use up more fuel faster so they have shorter lifespans. When these stars end their lives they become supernovas and then either neutron stars or black holes.
Brown dwarfs are stars who never obtain enough mass to become actual stars