Will things be fine in London, UK by July 5. I will be traveling from California to UK and was hoping things will be loosened?

Loosened, but there will still be restrictions.  There is currently a 2 week quarantine period in operation.

There will be a lot of restrictions I would advise you to cancel your holiday

Once again.....what is this, the 10th time you've asked?

NO ONE KNOWS......NO ONE KNOWS......NO ONE KNOWS.....NO ONE KNOWS.......NO ONE KNOWS........NO ONE KNOWS........

You will have to spend 14 days in lock down. If you have any sense cancel
the trip.

You will be in quarantine.

Everywhere will be hit so hard with COVID-19, that it will take ages for places to open up their borders and loosen the restrictions. There could be a second or third wave, who knows. Whatever you decide to do, be careful, stay safe and look after yourself. 

No, they won't be fine. The UK is still in the top 5 countries of new infections daily and in daily deaths and 2nd only to the US in total deaths.

No.........regardless of how many times you ask

Realistically; no chance. If you arrive on the 5th July, you'll be required to quarantine yourself for 14 days.