theyve had a bonfire going for the last three days in the garden. Previous neighbours never had bonfires. Theres also different lights on in the house and garden at night when ive walked past.
In London there are laws both on bonfires and on lights in the garden.
I suggest you google to find whether there are bonfire restrictions in your local authority area.
The rules on lights in one's garden probably apply everywhere. I know about them as our new neighbours in London (not British) put in garden lights hung from his trees and I thought how nice they were and that I might get some too. Then I discovered that that type of light was not legal.
Property rights take precedence and any lights in one's garden must not spill over into the neighbouring property. Your right to light in your own garden seems to apply a right to darkness too. Which is why in England most garden lights are at ground level or less than one metre high.
In our case we get on well with these neighbours. We told them we would not complain but would like them to switch the lights off when we go to bed (as they shine in my window) and to remove them when they sell the house.
If you may want to make a complaint (as we did with previous horrid neighbours) the advice from our middle aged daughter was to keep a diary of the nuisance you wanted to complain about. Then to send an informal note to the neighbours asking them not to continue and warning them that you may make a complaint if it continues. In our case that provoked a quite violent outbreak and the neighbour stormed into our house. Luckily one of his kids was a law student, calmed him down and the behaviour stopped.
The laws apply to behaviour that affects your own property. I am not sure one can complain if you only notice as you walk past in the street.
Covid has changed things a bit. People are under stress and in our road I am told there is reporting of people supposed to be breaking quarantine etc. Our nice neighbour drove his sick son to have a Covid test and was reported for breaking quarantine. The Gestapo had a man watching every block of flats and every street of houses. The Gestapo Police were quite few in number and relied on neighbours reporting people.
But your neighbours could also be of help perhaps? Here in London we have neighbourhood watch so unsocial behaviour can be reported to the street group rather than to the Police.