Is sperm alive/a life? If not, then how does it swim?

The sperm and the egg are alive.  But they are not a human life.  They must be combined to make a human life. 

Spermatozoa lives matter!

god rnakes it swirn

A spermatozoan is a living organism, and it swims by oscillating its flagellum (tail) rather as a tadpole does.

However, as the 18C Dutch microscope pioneer Leewanhoek showed, it is not a tiny version of the animal that made it, nor is an ovum, but a product of it in the same way as any cell of the body's tissues. Perhaps a better analogy is with the white blood-cell, which eats harmful bacteria and I think is a sort of bacterium itself.

Also, all but a very few of the millions of spermatozoa made by one male animal in its reproductive life, die without achieving anything. The only ones that fulfil their function are those that actually manage to reach an egg and fertilise it, and they too die in being absorbed by the egg. They are not sentient animals, only gene-carriers.

So don't get worried about killing them!