When I put key into ignition it will not start engine?

This sounds like a fuel issue. So, let's start with checking the fuel pressure and volume.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Basically, it sounds like the pressure is able to build sometimes but it is not consistent.

I would suggest also try and use starter fluid and see if the engine fires for a short time.

If it does then it is definitely a fuel issue, so we need to find this out first.

If that checks out, then here is a guide that will take us through the next couple of things to check:

https://youtu.be/dCjmRL3p4Cs

Please run through all this info and let me know what you find, and we can go from there.

Thanks