Congrats on your CAT C!
You can use indeed simply to find the agencies, then go to the agencies site and see if they have a branch near you. You don’t necessarily have to apply for specific jobs, you can just ring the agency they’ll tell you how to register and then they contact you when they have work.
I’ve been doing agency class 2 for the last 6 weeks leading up to my class 1 and I’ve done pallet work at a freight forwarding company, fridge lorries with cages and one place moving big crates with artwork in.
There’s a good chance you’ll come across somewhere you like and you might end up staying