For public liability join FPVUK or BMFA
You can also take their own theory tests which are the equivalent of te CAA registration test.
The tests are about your understanding of the drone code. Read that a couple of times and take the test. You should pass. If for some odd reason you misread some questions or tick the wrong boxes you can take the test again - as many times as you like.
Depending on the replacement value of your kit (often its just the aircraft that is lost not controller, batteries, case etc) you may find some insurance policies excessive. There are annual policies and pay-per-flight policies. Have a good search of the net. And check your household insurance too to see if you are covered there.
For places to fly, latest NOTAMs, airspace restrictions and directions to flying sites and nearby parking use DroneScene - and share your flying site discoveries to it!