Lawn Help?

Moved into a new build home a couple of years ago and I know they have problems with alsorts of rubble under the actual turf and layer of top soil. Currently my garden looks like this,
(Not the best pictures)





As I said not the best pictures but the grass is completely bald in patches.

Anybody know what the best option would be to take?


Thanks

 

Better pictures

 

Here's a link to one problem you have.
https://www.rhs.org.uk/advice/profile?PID=563

Looking at the rather nice pic of grass covered in white mould this could be the result of the other patches but it could also be other issues like compact soils, other diseases, situation and so on.
The problem with diseases on turf is that in many cases of turf issues more than one disease can be found.
Personally I can see what looks like White mould on other areas and would say that's a good point to start with at solving your issues.