i like gyproc easi fill 60 but its a powder you have to mix up.
these are good
Silverline Body Filler Application Set 4 Pcs - Screwfix
just sand the sharp corners off them if your a novice.
the screwfix own brand filler in the small tubs is decent. my entire living room is basically crafted out the stuff as the mongs that lived here before seemed to love using drawing pins to attach Christmas decorations and cards all over the walls so they were full of small holes.
i also like these
Fast Mover Tools, Foam Hand Sanding Block, Soft, 150mm : Amazon.co.uk: DIY & Tools
with mirka gold DA discs.
but if you have a DA with extract then use abranet discs on it.