I've never had too much trouble finding work here, but then I am also willing to accept low paying jobs and I've also learned the art of interviewing and telling people what they want to hear. I also know exactly how to blow an interview if I decide I cannot stand the interviewer lol.
It helps tremendously if you have a UK passport. Otherwise employers may not hire you, or they may be hesitant to. I never understand why people who move here don't become citizens. Seems reasonable for the UK to expect people who move here to do this. Least if they live here for a long time.
Anyway, if you are here and looking for work, Indeed basically lists most jobs in the UK. Make sure your CV looks good and doesn't read too "american". You're more likely to get a response the sooner you apply for a job once it's advertised online. Wait a week? it's probably filled. And you may have to send out 100 CVs until you get an interview or offer, especially if you have no UK work history. So be resilient.
If you do get the interview, great. That's probably just step number one. If you get through that, it's either some assessment or second interview. Or they may have you do a one day trial. Insist you get paid for this.
You should also be able to be flexible eg be able to work evenings and weekends and bank holidays. The more flexible you are, the more likely to get the job. Companies here are just not too flexible if you have small children, etc. Least I haven't found that to be the case. So many companies expect you to be available 24/7. Who is???
One thing I find quite annoying here is that they always ask how old you are. How rude lol. They also sometimes ask if you are married, and if you are white, or not. Straight, or gay. They say it's just for survey purposes, but not sure I believe this. I was once told by a male employer that he was about to put my CV in the bin after he saw that I was a yank (but he explained that because he liked my photo, which is also on my CV, he interviewed me. racist creep).
I was offered that job, and declined it. Cannot stand that mentality. Thankfully, most employers aren't like that, although they sometimes seem a bit paranoid that you are foreign (eg lack of trust, or worried that customers won't understand you, as if you don't speak English, or they worry you won't "fit in" with the team, which is entirely their own problem and they don't even see it).
And you always get asked "what made you come here". I mean, if you went to a hotel in Spain, would they ask you at the check in desk "what on earth made you come here"... If I had a pound coin for every time I was asked that.... I also find that a rude question but there it is, they always ask it. You can always joke and say "because I'm a glutton for punishment, gross inefficiency, passive aggression, and horrendous weather" but you may not get the job lol. Sometimes you have to at least initially be the "american" they expect you to be. Get the job, then be yourself. Shock horror lol. My God, we're not all alike. Years ago, shortly after I came here, I purposely blew a job interview because I didn't like the interviewer as he was a pompous little git and grilling me about being a yank, and I finally just said "yes well it's not long ago that I got off the boat" and you could see his face just sort of drop. It was quite amusing.
Unfortunately, UK companies are becoming more like American ones, meaning breaks are sometimes discouraged, long holidays are discouraged, etc. and you are often expected to work overtime. Didn't used to be like this here. Also, many companies will do everything but draw a blood sample. They will check your background, credit wise and criminal history, etc. Even for low level jobs. It's silly. And I was once told that my references "failed" when the person checking hadn't done her job (they hadn't failed at all), so be prepared for some absolute nonsense. Training dates set ,then changed last minute. Twice. That sort of thing.
And I have found most temp agencies a waste of time. Advertising fake jobs to get you to register. Not all, but many. So I would avoid them unless they are actually going to set up an interview for you with a real company.
Then, as many people smoke here, you find that the smokers are allowed to take a million breaks a day, while you are expected to only have your allocated breaks (usually half hour lunch and maybe one coffee break, if you're lucky). So they form a little smokers clique. Fair? No. But it's there. This is a country of drinkers, and smokers. They smoke at work, then drink after work. Culture. or lack thereof lol x