Engine cranks but does not start?

Hello,

So, the engine is cranking over but not starting?
Generally speaking, you will need spark, fuel and compression for the engine to start.
When you turn the key to the on position, can you hear the fuel pump prime for a few seconds?
If there is a fuel delivery issue, then the engine won't start even if the pump is good.
You can try spraying starting fluid into the intake and see if that lets you start the engine. If the engine starts for a few seconds then the issue is fuel.

Take a look at this helpful guide:

https://www.2carpros.com/articles/car-not-running-advanced

Let me know what you find or if you have any questions.
Thank you.

If it is turning over fast (the belt is turning), then as you are suspecting, the issue could be compression.
So, a good first step would be to check the compression.
https://www.2carpros.com/articles/how-to-test-engine-compression