Like so many science deniers, you're missing the point. Of course we need life* for evolution to happen but evolution does not depend in any way at all on how it got there and the evidence for evolution stands regardless of how life got going.
So the first life form could be due to one of the scientific abiogenesis hypotheses or any other reason you might want to make up: god-magic, planted by aliens, manufactured by life pixies all called Eric, whatever you want. Literally anything.
The point is the evolution happened afterwards and we have endless evidence that it did that puts it way beyond reasonable doubt. Even if the start was magic, science can and does tell us what happened next.
* Self-replication with inheritance and variation in a limited environment.
Your reasoning is flawed
First, creationists are not science deniers.
We love science but reject false science like evolution and billions of years.
Without a first living creature there are no living things.
And without a second living, there are no living things today.
The same goes for next 100 living creatures.
Abiogenesis is impossible. That is why evolutionists are scared out of their minds and try so desperately to hide from abiogenesis.
But they even try to skip the first 100+ living creatures.
So what was the first living creature and what features did it have?
But if you just want to start with evolution working in living things, then you need to start with the first living creature and show what was the second living creature and what features did it have?
then the 3rd, …