Just wanting to know what you think the problem is cheers

There are a great deal of possibilities. So, I am goiing to give you a diagnostic walk through for this situation.
When it talk about getting the trouble codes pulled and doing test such as testing the fuel pressure. Any Advance Auto or Auto Zone will pull codeds for freee and they loan out specialty tools and they will loan you the tool to do any of the tests mentioned in the walk through.
Just use the link below;

https://www.2carpros.com/articles/car-cranks-but-wont-start