My recommendations are ...

Islington Folk Club - Thursdays and not far from the centre of town - Hu(http://www.islingtonfolkclub.co.uk/ifc.html)

The Cellar Upstairs - Mondays and in The Alpaca pub on Essex Road, Islington (https://www.cellarupstairs.org.uk/),

Both are near tube stations.

A favourite venue of mine is Green Note on Parkway in Camden Town - well worth checking out who's on during your visit.

https://www.greennote.co.uk/events-page/


I must add for the record that The Sandman's recommendation of Loughton FC is rather off the wall. Loughton isn't even in London (it's in Essex) and is almost an hour's journey by tube train from the the centre of the city.