Welcome to the forum.
A lot to do with your question will relate to the airspace authority, in this case the CAA.
If using it for recreational purposes, you don't need to do a lot, register yourself and take a simple test of understanding rules etc.
You get a flier ID, simple online test of drone code / rules, free ?
Then register and label your drone(s).
You get an operator ID and you label your drone(s) with that number as per the guidelines.
Small annual fee for rego.
If you get any sort of reward for the video / photos of any sort of filming, or it is used for commercial reasons, then you need to get a drone pilots licence > PfCO.
I am sure you would need to do the labelling etc of drone(s), but you can have a look through here to confirm . . .
Information about all aspects of unmanned aviation
www.caa.co.uk
License and fees a lot higher, look into the site commercial section above if you think it applies to you.
Good luck, enjoy the forum and once you get registered etc, you can probably fly more at peace knowing you aren't going to get pinged by someone in authority (as you are outside current requirements).