A licence is not required to fly these aeroplanes, but training is advisable, and third party insurance is required.
Formal training is available from the BMAA and the BHPA, insurance is then available on joining the BHPA.
If you do decide to do formal training at a later date, you can then register your sub70 with the CAA as an SSDR, and then your flying hours can be counted in your licence.
If no formal training is undertaken insurance can be obtained from Traffords or Axa
http://www.traffords-insurance.co.uk
http://www.flugschulen.at/axa/english
BMAA Schools and Clubs
https://www.bmaa.org/try-microlighting/schools-and-clubs
BHPA Schools